Category Archives: Winter gardening

Rabbits!

rabbit-717855_960_720With apologies to Bugs, Peter and Thumper, rabbits are real pests in the garden. Parts of the Denver metro area are inundated with them, while others are not – at least yet. I’ve been seeing them in my central Denver neighborhood for the last few years. They reliably devour my lettuce each spring  and feast on Goldstrum Rudbeckia in August.

If you’re not sure if rabbits are the culprits to your plant damage, look for clean, 45 degree angle cuts, mowed down seemingly overnight. Damage is usually up to 24″ high and most often on tender new growth.

While a hungry rabbit will eat many plants, in the vegetable garden they prefer young tender shoots of lettuce, beans, squash  and broccoli.  They also love to munch on many ornamentals such as black-eyed susans, pansies, marigolds, petunias, gazania and ornamental grasses.

Nothing will completely deter a brazen bunny, but a combination of the following practices may curb their ways.

Fencing – Erect 3′ high barriers with chicken wire with 1″ mesh openings around your garden plots. Rabbits love to burrow, so be sure to bury the fencing 6″ deep.

Plants – Colorado State University reports that sedum, foxglove, iris, lambs ear, red hot poker, yarrow, yucca, apache plume and blue mist spirea are somewhat rabbit resistant. Rabbits’ taste buds vary just as ours do, so no plant is 100% off-limits.

Predators – Wildlife such as foxes, coyotes, hawks, adult owls and rattlesnakes will send rabbits packing. So will your cat or dog, who will get the added benefit of a good workout from chasing bunnies.

Repellents – Products containing capsaicin (pepper extract) , castor oil, ammonium salts or predator urine can be effective when sprayed to a height of 3 feet and reapplied after heavy rains or watering. Some newer eco-safe sprays deter rabbits and deer, are less effected by moisture and emit a long-lasting scent (undetectable by humans) which repel rabbits. These are not recommended for edible plants.

Winter Care – Rabbits feast on our landscape in the winter by chewing on woody shrubs and the bark of your trees (fruit trees are a favorite). Protect these plants with fencing. Also remove thick underbrush and tall weeds and grasses which create comfy winter shelter. Seal up openings around decks, sheds and crawl spaces, too. By removing an inviting resting place, rabbits are encouraged to seek shelter elsewhere.

Have you had success in preventing rabbit damage?

References:

http://planttalk.colostate.edu/topics/wildlife-issues/2305-ravishing-rabbit-revenge

http://www.denverpost.com/2013/06/19/bunny-rabbit-plague-hits-colorado-gardens-what-to-do/

Photo Credit:

www.Pixabay.com, a source for royalty free images.

Written by Linda McDonnell, Denver County Master Gardener

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Grow Greens Indoors this Winter

January can be a tough month for gardeners. Thumbing through seed catalogs is a nice diversion for a while, but then what?

Instead of using your green thumb to turn pages in a catalog, you can stretch it with a couple of easy indoor gardening projects. Each of these projects takes minutes to plant, and in a few weeks you’ll have something delicious, green and growing in your kitchen. You probably already have most of the supplies to get started today.

Garlic greensPlanting Garlic Greens

While this indoor herb planting won’t grow garlic bulbs, you’ll get several cuttings of tall greens. These greens add a delicate garlic flavor to stir fry dishes, green salads or any favorite recipe.

Materials:
Small container of potting soil
Saucer to catch excess water
Garlic cloves (old or new)

Instructions:
1. Place a paper coffee filter to cover the container hole.
2. Fill container with potting soil and add water to moisten the soil.
3. Separate the garlic into individual cloves; leave skin on.
4. Arrange the cloves in the container, planting 1-2 inches apart.
5. Push cloves into the potting soil, about 2/3rds of the way in, pointed end up.
6. Water in; place the container in a window or spot with indirect sunlight.
7. Keep soil moist and you’ll see the garlic sprout in about a week or so.

When the greens are 6 inches tall, clip and use. The cloves will keep growing for at least several more cuttings.

micro greensPlanting Micro Greens

Micro greens can be planted outside in early spring, but they can grow indoors, too. These small green leaves are tasty and nutritious when used to top green salads, sprinkled into sandwiches instead of lettuce, stirred into omelets or any other way you’d like to eat them.

Materials:
1 packet micro green mix or sprouting seeds like broccoli or pea (check with your favorite garden center, natural grocery store, or order online)
1 shallow plastic container with holes punched in the bottom (like a clear lettuce or spinach container, minus its lid)
1 tray or second container to catch any excess water
Loose, well-draining seed starting mix or potting soil
Spray bottle

Instructions:

1. Punch small holes in the bottom of the container for drainage; cover holes with paper coffee filters. Place the container on tray to catch drips.
2. Fill container with several inches of soil (about 2 or 3 inches).
3. Moisten the soil; allow excess water to drain and discard.
4. Scatter seeds over the top of the soil; cover with a thin layer of soil.
5. Use a spray bottle to moisten seeds.
6. Place container on a sunny windowsill or under grow lights placed several inches above the top of the plants.
7. Keep soil evenly moist, but not overly saturated; don’t let seeds dry out.
8. Look for seeds to sprout and grow their first leaves in about a week or two.

When plants are about 2 inches tall and have one or two more sets of leaves, use scissors to clip greens and enjoy.

Do you have an indoor gardening project that keeps you busy in winter? Please share your ideas here!

By Jodi Torpey
Denver master gardener

Botanical Ice Lanterns

I can’t wait to try my hand at making these unique botanical ice lanterns. All that is needed are a few readily available supplies, cold weather (or a freezer) and a bit of nature’s beauty. Detailed instructions for creating them can be found at gardenista.com, photos courtesy of Erin Boyle.

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Posted by Linda McDonnell, Denver County Master Gardener