Category Archives: Fall gardening

Never Put a $10 Plant in a 10¢ Hole and Other Gardening Tips From Denver Master Gardeners

planting-1898946_1920Passionate gardeners love to talk about gardening, so with that in mind, we recently asked Denver Master Gardeners for their best gardening advice. Responses included tried-and-true practices, creative suggestions and good reminders for all of us as the gardening season kicks into full gear.

As the title of this post implies, we believe that great plants come from appropriate soil preparation. Amending with compost is often imperative as soil in our region tends to lack organic matter. But proceed with caution, as some plants, such as natives, prefer a leaner, less fertile soil. Too rich soil will cause these plants to underperform and often just flop over. It pays to do a little homework before planting, read seed package directions and have your soil tested.

One of our gardeners shared her recipe for amending soil: Add 1/2 a handful of both Alaskan fish pellets and triple super phosphate to half a bucket (such as a kitty litter pail) full of compost. Mix this into the planting hole for strong root development and beautiful blossoms.

A tip borrowed from the Rock Garden Society is to plant bare root. By gently shaking off most or all of the soil that the plant is purchased in, the plant will adjust to the garden soil without the soil interface (or boundary) that can occur between two soil types. Bare root planting promotes healthy root development.

mulch-1100555_1920Mulch, mulch, mulch is the mantra of many of our survey respondents as it keeps weeds out and moisture in. Add it like crazy each time you dig in the veggie, perennial and annual gardens and don’t forget container plants too. Small to medium-sized bark chips are popular, practical and pleasing to the eye. Natural mulch options are very effective, including not quite finished compost from the compost bin which will add carbon, feed living organisms, prevent water runoff and prevent compaction. Local arborists are often willing to drop off wood chips which would otherwise fill up the landfill. In the fall, mow over your leaves and spread them throughout the yard, they’ll breakdown by spring and add organic matter to your soil. Consider purchasing a chipper to grind up branches and other garden waste.

garden-hose-413684_1920Suggestions for responsible use of water include watering when the plant needs it instead of on a set schedule. Soaker hoses, often made from recycled material, are effective for watering plants at the soil line. Plants (even xeric ones)  need moisture to maintain healthy roots and overall strength, but often less than we think. For example, the Water Smart Garden at the Denver Botanic Gardens is watered about seven times during the season.

Weeding can feel like a no-win battle, but attacking weeds after a soaking rain makes the task easier. Pull weeds and unwanted volunteer shrub and tree seedlings when they are small, before they take hold in the ground or develop seed. Add stepping stones to the garden to avoid stomping on plants and compacting soil when working in the garden.

bindweed-1207738_1920A clever tip to eliminate stubborn weeds, such as the nasty bindweed shown here, is to take a large piece of heavy cardboard, make a cut from the edge to the center. Keep the cardboard as level as possible, slip the vine in the center and spray the vine with the herbicide of your choice or horticultural vinegar, which is sold in garden centers. The cardboard will protect surrounding plants from overspray. Aggressive weeds may require multiple treatments during the season.

One of our members recommends a tomato planting technique passed on through generations of farmers. She adds blackened banana peel to the soil and feeds them with skim milk upon planting and again one month after that. This less conventional practice yields her sweet, abundant fruit. While CSU can’t vouch for the scientific efficacy of this, the banana could be adding potassium and the addition of calcium may reduce the chances of blossom end rot.

plant-1585251_1920Growing tomatoes in containers is recommended for those with limited space. Select varieties which produce smaller fruit such as Patio, Cherry or Sungold. Use a large container (18+ inches in diameter), a sturdy support and a tray with casters. This allows plants to be moved from the path of hail or to optimal conditions. Container plants of all kinds benefit from weekly feeding of 1/2 strength fertilizer.

To keep pests at bay, try a thorough weekly spray of water during the growing season, including the walls of the house and fence. It’s a kinder way to shoo pests away.

If your vines need a sturdier trellis consider building one out of remesh, which can be found at hardware stores. It makes a durable, cost-effective support and can easily be cut with bolt cutters. It also can be attached to supports to create a dog run or create plant cages.

botanical-garden-413489_1920In the flower garden, invest in perennials for texture and dimension and add annuals for bold color. “Enjoy the randomness of some plants that choose their own spots to thrive” suggests one gardener. What a positive way to think of the seedlings that sprout up at this time of the year. Remember, too, that perennials may not come into their glory until the second growing season.

Gardening is a four season hobby. Winter watering of trees and shrubs will help keep them healthy and  veggie gardeners can get a jump on the season by using a cold frame or floating row cover to get an early start on lettuce, spinach and other cool season crops. Fall is a fantastic time to fertilize, aerate and over-seed the lawn. It is also an ideal season to divide perennials so that they settle in and are ready to take off in the spring.  Share your divisions with your neighbors, too, or trade for plants you’ve admired (envied?) in their yards. If you need more gardening space, solarizing or sheet composting is an excellent technique to ready a new garden bed and can be started throughout the year.

And lastly, a veteran gardener advises us to “Remember each little garden flower or planting arrangement is a moment in time. It will change. Don’t worry about it or take it too seriously.”

 

Written by Linda McDonnell with thanks to the many Denver Master Gardeners who shared their advice.

All photos courtesy of http://www.pixabay.com, a source of royalty free images.

Fall: The Science of Color and Options for Clean-up

In Colorado and many other states in the US, we enjoy fabulous fall color in our gardens, parks and wilder landscapes.  We notice it most on trees, but many shrubs and other plants change color in the fall too.  Have you ever wondered where all that color comes from?  Why do the leaves drop off the trees?  And what use are all those huge drifts of dead leaves to us?

Color

Most plants have green leaves.  This is because chlorophyll in the leaves absorbs the red and blue parts of the light spectrum but reflects green light-waves so we see “green”.  Chlorophyll is used in photosynthesis.  This is the chemical process by which plants convert light, carbon dioxide and water into oxygen and carbohydrates – i.e. food for the plant. Chlorophyll is an unstable compound and the plant continuously replenishes it throughout summer when good sunlight and high temperatures prevail.

When temperatures cool and nights lengthen, chlorophyll production stops and so does photosynthesis (the plant’s food production system). As the green-reflecting chlorophyll disappears, other colors “appear.”  In fact, these colors were always present in the leaves but now they are no longer masked by the green light-waves reflecting from the chlorophyll.

Carotenoids absorb blue-green and blue light and reflect yellow light waves.  This is perceived by the human eye as yellow or greenish-yellow.  This is why the fall color of birches and aspens is yellow.

Anthocyanins absorb blue-green, blue and green light and reflect red light-waves.  This is perceived by the human eye as red through to purple.  This is why the fall color of red oaks, sumacs and some maples is red.

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Acer tartaricum ‘Hot Wings’ still green

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Acer tartaricum ‘Hot Wings’ turning red

 

 

 

 

 

 

 

The depth and shades of fall color depend not only on the presence (or absence) of these pigments, but also the temperature and sunlight available.  Low temperatures and bright sunlight destroy chlorophyll.  So, falls with dry, sunny days and dry, cool nights tend to produce the best fall color.

In severely dry falls, the lack of moisture available to the plant may mean that leaves simply die without producing their usual fall colors of yellow, red or purple.  The leaves lose so much moisture that the normal chemical processes cannot continue and the leaves dry, turn brown and drop early.

The ‘Fall’

Once the spectacular show of fall color is over, deciduous (i.e. leaf-losing) trees and shrubs drop their leaves.  Cooling temperatures and lengthening nights trigger plants into sealing off the point on their stems where leaves are attached so that no more exchanges of moisture and nutrients between the leaves and the rest of the plants are possible.  This is called the “abscission layer”.  When this layer is complete, the leaves drop (or “fall”).

What use are those dead leaves?

Think about how nature deals with this “problem”.  Leaves fall from trees to the ground of the woodland, forest, mountainside, meadow – wherever they are situated.  Rain, frost, snow, the trampling of animal feet all help to break the leaves down into smaller and smaller pieces.  A huge drift of fallen leaves decreases significantly in size as air spaces between the leaves diminish.  An army of creatures from the soil surface, and from beneath it, break down the leaves further through eating and excreting them (think: earthworms, beetles) or chemically decomposing them (think: fungi, bacteria).   In this way, the dead leaves are decomposed into the tiny elements that create soil.  It’s a mixture of humus and minerals.  The humus is the last vestiges of the leaves that are hard to break down like cellulose and the minerals are the chemical components of the leaf tissue, e.g. nitrogen and carbon.

The humus and minerals help to form new soil structure in which new plants can seed, germinate, develop and continue the cycle.  The new fertile or replenished soil provides the moisture and nutrients that the now-leafless trees will need to survive winter and re-start photosynthesis and growth in spring.

How to deal with those huge piles of leaves

We’ve seen above that the dead leaves have an important part to play in the garden’s eco-system.  So, what can you do?

  • Just let the leaves remain where they drop on garden beds. They provide great mulch to maintain soil temperatures and protect plant roots and will rot down over winter, improving your soil as they go.
  • Leave a thin layer of leaves on lawns. Rake or blow them off (if you must) but a thin layer of leaves (especially if you run over them once or twice with the lawnmower) will break down quickly and help re-vitalize your lawn.
  • Rake or blow leaves off walkways, drives and sidewalks on to adjacent garden beds, so that these hard landscape areas are visible and don’t become slippery. Do not sweep or blow leaves into the street, as they can cause serious blockages in street drainage systems.
  • For a neater look, you can blow the front edge of borders clear, letting the leaves accumulate at the backs of borders and behind and below larger plants.
  • Put layers of leaves in your compost bin (even better if you can run the lawnmower over them first) between your layers of green garden/kitchen waste.
  • Save the leaves in plastic trash sacks (stored in an unobtrusive part of the yard) and let them rot down over winter, to be returned to the garden when they have decomposed. This leaf mold (the lovely dark brown material you get from decomposed leaves) is like “gold-dust” to the soil.
  • Save the leaves in an open cage made of upright posts and chicken wire to decompose – more “gold-dust”. If you have room, let your neighbors drop their leaves in the cage too.
  • BUT if leaves come from a diseased plant e.g. one with powdery mildew, black spot (roses), apple scab, anthracnose, they should be collected up and disposed of as garbage to help prevent re-infection in the next year.
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Leaf cage made from old timber and chicken wire

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Fallen leaves make great mulch (and are warm and cosy for the dog!)

If none of these options work for you, you can dispose of the leaves in degradable paper sacks which are usually available from your local hardware store at this time of year.  The sacks can be collected with your normal weekly trash service.  Some towns and cities will have leaf drop-off points where you can take the bags for the city to collect.  The city will then use the leaves to make leaf mold for local parks or otherwise dispose of them.  If you can’t do these things yourself, look for a local lawn service company that can, or hire a local teenager to help.

But, whatever you do, remember that the leaves really belong on the ground.  That’s nature’s way, after all.

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Acer saccharinum (silver maple) turned yellow

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Quercus rubra (young red oak) turned red

Anne Hughes/Denver County Master Gardener

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sheet composting or … cooking up an experiment in the garden

I’ve always known that the soil in the garden was the key to planting success.  So, when we started our new Denver garden in 2014 we turned in most of the turf and dug, weeded and added leaf mold to the topsoil.  (We had kept all the fall leaves for this purpose.)  Then all the bare soil was covered with a 3-4 inch mulch of wood chips.  Key trees were planted in spring 2014 with more trees, shrubs , ornamental grasses and herbaceous perennials following in 2015.  We watered diligently till the winter and snow came.  We thought we’d made a good start.

In spring 2016 I was delighted to see our young trees and shrubs budding out .  Most of the herbaceous perennials had survived, but they didn’t increase in size during the summer. They hardly bloomed.  They didn’t die.  They just sat there.  Watering seemed to make no difference.

I figured that the larger plants (trees and shrubs) were able to get their roots down into the clay where there was more moisture and more nutrients.  But the perennials were struggling with their smaller root balls being mostly in the 8-10 inches of sandy loam topsoil.  Here water drained away quickly and despite the wood chip mulch, the unrelenting sun and high temperatures baked the soil to an iron hard cap over dull powdery stuff below (if you could get the spade in that far!).

I had a soil test done by the soil laboratory at CSU which told me that our topsoil was low in nitrogen and organic matter.  Ah-ha!  That is why the plants weren’t thriving.  The lack of nitrogen was slowing the development of stems and leaves.  The lack of organic matter meant the soil wasn’t holding sufficient water for the plants’ roots to take up.

OK, I thought, we have to do more to improve the soil. I’ve never liked the idea of just throwing chemical fertilizers at the garden.  It’s expensive, wasteful and potentially dangerous to the wider environment.  Double-digging and adding store-bought amendments (of uncertain quality) is back-breaking and expensive. What to do?

Soil is not tilled in the natural world.  Fertility is built up by the decomposition of leaves, twigs and other plant waste on the surface.  Soil texture and nutrient levels are also improved by the actions and decomposition of organisms living in the soil and plant roots.  I’d just been reading about permaculture gardening techniques and the soil improvement technique of “sheet composting” or “lasagna gardening” seemed to be what we needed.

This is a way of building up organic matter and nitrogen in the soil without digging.  You gather different sorts of compostable material (green garden waste, compost, grass clippings, straw, dried leaves, well-rotted manure are just some you can use) and pile them up on the soil in layers.  Hence “sheet” composting or “lasagna” gardening. Essentially, you are making compost directly on top of the soil rather than in a compost bin elsewhere and then transferring it later to the garden.

Many books suggest that you also lay newspapers or plain cardboard down first to smother any existing weeds in the ground.  This is usually where you are trying to improve a weedy, uncultivated area.  But such two dimensional materials can be a barrier to the passage of water, nutrients and the essential soil creatures (see below) that you need to make the process work.

Cardboard layer to start

Cardboard layer to start. Existing wood chips raked on to path first.

Cardboard often incorporates waxes which inhibit the movement of moisture and make it hard to break down.  Shredded newspaper in half inch layers may be a better alternative, but not perfect.  I did use cardboard, but in hindsight probably didn’t need it as the soil was not weedy at all.

Every layer has to be thoroughly soaked with water including the existing soil.  The fungi, bacteria, insects, beetles, earthworms etc. that will break down your materials need water to do their work.

My “recipe” comprised from bottom (soil level) to top:

  • cardboard (on reflection, probably not needed)
  • garden compost (precious stuff from my own bins)
  • grass clippings from a neighbor’s “pile” and half a bag of left-over peat moss
  • partially decomposed garden waste from another neighbor’s “pile”
  • wood shavings and straw from another neighbor’s old chicken shed
  • grass clippings again
  • leaves collected in our leaf cage from the previous fall
  • more partially decomposed garden waste
  • wood chips to hold it all in place and for aesthetic appeal

The layers amounted up to about 12 inches of material.  Each layer was watered in.  Grass clippings were laid in approximately 1 inch layers while the other materials were laid in 3-4 inch layers.  You need much more brown material by volume than green.

Straw and partially decomposed garden waste

Straw and partially decomposed garden waste

Just like making compost conventionally it is important to have a mix of “green” and “brown” materials or, in chemical terms, sources of nitrogen and carbon.  Too much green (e.g. grass clippings) and you have too much nitrogen.  Too much nitrogen will encourage leafy top growth in your plants at the expense of root and fruit/flower development leading to straggly unhealthy plants.  Too much brown and the materials won’t break down sufficiently.

But the green/brown or nitrogen/carbon balance isn’t just about your plants.  All the living creatures in your soil need the right balance too.  They have to live, multiply, work the soil, die and decompose in order to release the precious nutrients to your plants.  The soil creatures need to feed before your plants can.

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Last year’s leaves go on

It’s important that the materials you bring in don’t also bring in weed seeds resulting in a huge weeding problem for the next year.  But the theory is that any weed seeds that do come in will rot in the damp condition of the layers. And if they don’t rot first, they won’t germinate anyway due to lack of light.

The biggest part of this job is sourcing and gathering all the materials.  There were many trips to neighbors’ gardens with rakes and shovels.  Then the trips home again with a car full of other people’s “waste” in old plastic bags. It is hard work.

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The finished thing

So, now we have some 60 feet of garden borders resting for the winter under their layers of composting (we hope!) materials.  We also have many other areas where fewer layers were used (mainly straw with grass clippings or partially decomposed garden waste) to about 3-4 inches to perk up the soil around and between trees and shrubs.

Many questions remain:

  • Will the cardboard decompose?
  • Is the “green” and “brown” balance right?
  • Will the raccoons and skunks churn it all up?
  • Will there be a crop of new weeds from the imported materials?
  • Will the cold Colorado winter simply stop any decomposition from taking place?
  • Will there just be a smelly slimy heap to remove next spring?
  • OR, will we have achieved that elixir of gardening – fertile, well-drained, moisture-retentive soil???

Well, the answers to all these questions will be given next year when I report back in another post.

In the meantime, what do you think? Have you tried this? Did it work well? Please share your comments below.

Anne Hughes  – Denver County Apprentice Master Gardener

Fall in the Perennial Garden: The Case for Less Clean Up

Mid Summer BorderI don’t know about you, but in my perennial garden, fall cleanup can be hit or miss. Whether a function of limited time, gardener burnout or an early cold spell, some years I just let it all freeze dry in place till the spring. What I’ve found is there are some really good reasons to do less fall clean up and I’m not as lazy as I once thought.

Here’s the case for leaving most perennial flower garden cleanup for the spring:

  • Dried foliage will help protect the crown of perennials from the freeze/thaw cycle; this is especially good for marginally hardy perennials. If  you decide to prune, leave about 3-4 inches from the ground to avoid damaging the crown.
  • Dead stems “mark” the plant and lessen the chance of accidentally digging it up or stomping on it in the spring. This can be really helpful for plants that wake up a bit later each spring (Threadleaf Coreopsis does this in my garden).
  • Plants may drop seeds and give you additional seedlings to love or give to friends next year. Such was the case with the Black Eyed Susan’s/Goldsturm Rudbeckia in the photo above.
  •  Seed heads provide tasty food for birds.
  • Enjoy the natural beauty of the winter landscape such as the ornamental grasses moving in the wind and the various colors and textures of foliage, which can be especially lovely when covered with a dusting of snow.

Bright pink Salvia Greggii /Wild Thing Sage. This semi-woody plant should be pruned in the spring. Photo courtesy of PlantSelect.org.

  • Some plants highly prefer spring pruning, such as grasses and plants with semi-woody stems such as Munstead Lavender and  Wild Thing Sage or Salvia Greggii. A spring haircut when new growth emerges often yields a plant with better form and growth. (Not to mention increased chance of winter survival).
  • Early season flowering shrubs such as lilac have already put on the growth that produce next year’s flowers. If you cut now, you will not have blooms next spring. These plants should be pruned soon
    Lilacs which were side pruned too late in the season. Photo from CSU CO Master Gardener Garden Notes #616
    Lilacs which were side pruned too late in the season. Photo from CSU CO Master Gardener Garden Notes #616

    after they are done blooming. A good general rule for lilacs is prune no later than July 4th.

Now, having said all that…here are beneficial fall care tips:

  • Cut back overly assertive perennials whose seedlings take over the garden and become a nuisance. Denver Gold Columbine and Walker’s Low Catmint are prime examples in my garden.
  • Remove leaves of plants that had powdery mildew or other foliage diseases. This will cut down the chance of the problem festering in the soil and re-emerging next spring.
  • Trim long rose canes  which can get damaged by the wind, otherwise don’t prune roses.
  •  Apply light mulch after plants have gone dormant, usually after a few hard freezes. Avoid packing mulch down too tightly so that beneficial moisture can reach the plant and the mulch does not spawn mildew or mold.
  •  Water during dry spells.  When there is little fall/winter precipitation  give the landscape a drink once a month, when temps are over 40 degrees and as early in the day as possible.

Personal preferences vary, so do what’s right for you. Just don’t beat yourself if you kick up your feet and leave most of the chores till the spring!

References for this post:

Winterizing Perennials, Plant Talk 1020

Maintaining Perennials, Plant Talk 1019

Winterizing Perennials During Drought, Plant Talk 1064

Written by Linda McDonnell, Denver County Master Gardener

Pass-Along Plants

Many plants in my garden came from the gardens of friends.  I call these pass-along plants.
The Ginnala maple in my back yard is turning red and today the leaves are blowing off. This tree came from Virginia’s yard as a “stick” not quite 1 foot tall.  I managed to over-winter it for a few years on my back porch, moving it to a larger pot as needed.  Now it provides a hiding place and a launching pad for the little birds that eat at my bird feeder.  Ginnala Maple
Also in my back yard is the rhubarb plant that Patti brought back from her parents’ farm in Iowa.  It has done well here, in Denver.
The walk to my front door is lined with Maximilian sunflowers. These tall, happy perennials came from Jane’s yard. They tend to spread on their own, which makes them a good pass-along plant.
Perennials that spread and self seeding annuals are wonderful gifts if the giver warns the next gardener about the plant’s habits.

The story of the pass-along plant can live on after both gardener and garden are gone.  Take a minute to remember or to plan the pass-along plants in your garden.

Why Leaves Change Color

Fall leaves

Autumn, when the trees blush at the thought of stripping naked in public.”
– Robert Brault

Well, that’s a new way of thinking about fall leaves, isn’t it? In reality, the changing colors of leaves is a complex dance between reduced daylight, temperature shifts and moisture. These climactic factors trigger deciduous plants to prepare for  winter dormancy, with each species changing colors on its own timetable.

When temperatures begin to moderate and daylight decreases, it is a signal for plants to decrease and ultimately stop the production of chlorophyll, which in turn DSCN0428[1]triggers sugar storage in leaf cells, which is needed for winter survival. Chlorophyll is responsible for leaves’ green color, so in its absence, other pigments, which were always present are now “unmasked”. Two such pigments are carotenoids, responsible for the yellow in corn, carrots and  aspen and anthocyanins, which produce color in apples, strawberries and some maple trees.

Why are the fall colors more brilliant some years than others? Weather, both before and during the time chlorophyll production slows down, plays a key role, for example:

  • Long winters or  severe summer drought can delay fall color for a few weeks.
  • Moist fall weather and cooler temperatures keeps leaves bright and colorful longer.
  • Dry autumn conditions results in earlier loss of color, drying and dropping of leaves.

Parts of the Colorado  high country have been ablaze with golden aspen for a few weeks now, while other areas, including the Denver metro area, have yet to peak. The U.S. Forest Service offers a  Fall Color Hotline at 1-800-354-4595, while the map below shows typical time frames for various regions.

fall_peak_us_720x486

For more detailed information on fall leaves, be sure to check out:

www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm

www.ext.colorstate.edu/ptlk/1728.html

Submitted by Linda McDonnell, Denver Country Master Gardener

Paperwhite Narcissus – An Indoor Bulb

The paperwhite narcissus (Narcissus papyraceus) is  a type of daffodil that can be forced to bloom indoors during Colorado’s winter.

It is usually available in garden centers as soon as the spring bulbs are for sale.   The bulb can be planted in potting soil, or nestled in pebbles or glass marbles.  The pebbles help you arrange the bulbs and keep their “heads” above water.  You could use sea shells, plastic building blocks, plastic figures or animals — try anything that is waterproof.  The roots will grow down into the pebbles.  Pull the pebbles out of the roots when the bulb has finished blooming.

If you decide that a different container would work, the bulb will not suffer at all if you take it out and rearrange it.  You can also buy Paperwhite Kits with a pre-planted container.  All you do is add water.

The plants can grow to more than a foot tall.  Tie them loosely to a stick or tie them together as shown in the photo below (© Colorado State University Extension, Planttalk 1322.)    If the bulb receives bright, indirect sunlight it will not get quite as tall and “leggy”.

I like to put the bulb, marbles and water at the bottom of a tall glass cylinder. The vase contains the leaves and keeps them from toppling over. Once the bulb has bloomed you can choose to cut the bulb off the bottom and arrange the flowers in another vase.

Paperwhite narcissus

It takes 4 to 8 weeks for the bulbs to bloom.  In my experience they bloom quicker in the Fall and more slowly in late Winter.  If you start a new bulb every few weeks you will have continuous flowers.   The bulb blooms only once so throw the bulbs away when the flowers wilt.

WARNING: Their fragrance is very strong.  If you don’t like it – give it to the first visitor to admire the scent.  Or put them in a common area with a sign that says “Free” or “These flowers need a new home”.  You might make someone else’s day! 🙂

For more information go to the Colorado State University Extension Service, Planttalk #1322.

Plant Spring Flowering Bulbs Now – You’ll Thank Yourself Later

yellow tulips

Photo courtesy of Jodi Torpey, WesternGardeners.com

Like many gardening tasks, tulips, daffodils, crocus, hyacinths and other spring bulbs demand our patience. Plant now and next spring you’ll  reap the rewards of abundant beauty. It’s a good lesson in delayed gratification!  Here are a few tips to insure success.

When to Plant

Mid to late September is ideal as the bulbs have time to develop a strong root system before a hard freeze, but can be planted into October if weather permits. Garden centers have the best selections in mid September so if needed, purchase early  and store in a cool, dry place until you can get them in the ground.

Where to Plant

You’ll want a mostly sunny location with good drainage as bulbs can rot in soggy soil. Consider where you’ll enjoy the blooms the most and what other spring flowering perennials or shrubs the bulbs will compliment. Perennials such as  pure white candytuft, (Iberis sempervirens),  lavender or pink creeping phlox (Phlox subulata) or stunning basket of gold alyssum (Allyssum sempervirens) pair nicely with mid-season bulbs. You may find some great deals on these spring blooming perennials at the local garden center right now, or divide some plants already in your beds.  Some bulbs bloom simultaneously with flowering shrubs such as forsythia (early bulbs), lilacs (mid to late bulbs).

After blooming, bulb foliage should be left on the plant to die back and re-nourish the bulb. This foliage can be camouflaged by emerging perennials or annuals, so it’s good to plan for this step now.

How to Plant

Bulbs are planted with their necks up and their hips down; a good rule of thumb is to plant 4 times the height of the bulb. Amending soil with organics such as spagham peat moss or compost is recommended. Bulbs, like most plants, won’t thrive in compacted soil.

Iris Reticulata courtesy of Jodi Torpey, Westerngardeners.com

Iris Reticulata courtesy of Jodi Torpey, Westerngardeners.com

Research at CSU has shown that in our region, Super Phosphate is the most effective fertilizer for bulbs and should be applied at the root base and in the loosened soil below the bulb so that the nourishment can be absorbed. Further, CSU’s studies indicate that bone meal is not effective in our soils, although it is frequently sold alongside bulbs.

For thorough information on soil prep, care and a planting depth chart visit

Fall-Planted Bulbs and Corms and PlanttalkColorado Bulbs:Spring Flowering

What to Look For When Selecting Bulbs

There are a wide variety of pre-packaged selections of tulips, daffodil (narcissus), hyacinths and alliums to name just a few.

Giant Alliums courtesy of Jodi Torpey, WesternGardeners.com

Giant Alliums courtesy of Jodi Torpey, WesternGardeners.com

When buying packages of bulbs, be sure to  inspect the them to insure they  are firm, uniform in size and large for the type (compare to the open bins of like bulbs is a good idea) and unscarred. Many bulbs are sold from boxes so you can make your own selection. By mixing early, mid and late bloomers of varying heights, colors and textures, you can have a spectacular start to next year’s gardening season. Just be patient.

Submitted by Linda McDonnell, Denver County Master Gardener

Balcony Gardening – Grow A Salad Bowl

Now is a good time to plant baby lettuce, spinach and micro-greens for early Fall harvest.  You do not need a deep container to grow salad greens and you can grow the greens from seed.  Covering the potted seeds with loose plastic wrap holds the moisture and heat and encourages sprouting.

Growing Container Salad Greens:  “You will be able to harvest your first crop in just a few short weeks, using the small tender leaves that are often not available to buy. These micro-greens are the mix of choice for gourmet salads. Leafy greens also make a flavorful addition to sandwiches or wraps.”

Salad greens

Radishes also mature quickly.  Use radish greens instead of basil in your pesto recipe.Radishes

As a container gardener you can quickly move your salad bowl inside if we get a sudden Colorado frost.  In a sunny window you can keep growing salad all winter.

If you need an incentive, a CSU Extension publication lists the nutrients in different salad greens and has notes about taste.  It has great photos — I can now identify Mizuna.  Enjoy!