Category Archives: Container 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.

CSU Webinar Helps Solve Garden Mystery

Deformed tomato leavesEvery summer is different in the garden, but this year I found something I hadn’t seen before with two container tomato plants. The new leaves on these  plants was stunted and twisted into odd shapes.

Like many gardeners, I’ve seen plenty of tomato problems in my garden over the years. Early blight, late blight, blossom end rot and insect damage have cropped up from time to time, but these twisted leaves had me stumped.

I looked for images of similar problems online and checked my Tomato MD app, but I couldn’t find anything else that looked like that deformed growth.

In a great gardening coincidence while I was finishing my Colorado Master Gardener continuing education requirements, I clicked on a Small Acreage Management (SAM) webinar, and the mystery was solved.

These SAM webinars are posted on YouTube, so any gardener can watch them for free. The one that helped me diagnose my tomato plant problem is called “Herbicide Carryover and Fall Garden Care” led by Darrin Parmenter of CSU Extension in La Plata County, dated Sept. 4, 2013.

Herbicide carryover can happen when gardeners use herbicide-treated hay, straw or grass clippings as mulch or compost in their gardens. Herbicide carryover can also occur if gardeners apply manure from livestock that ate treated pasture or crops. Tomatoes and members of the tomato family are especially susceptible to herbicide carryover.

I’ve used well-aged horse manure in my garden for years and there’s never been a problem until this season. It turns out that herbicide carryover from horse manure is the top pathway because herbicides can pass through horses so quickly.

As soon as I understood the problem, I started a remediation program to improve soil microbial activity in the two containers with the affected tomato plants. I’ve cultivated the soil to increase oxygen, added a different kind of organic matter to increase beneficial soil organisms and used a home-made organic mulch. I’m also keeping the soil evenly moist and using a liquid fertilizer once a week.

According to Darrin in the webinar, the tomato plants may recover if there’s enough vegetative growth. I’m certainly going to be more thoughtful with how I amend my garden soil in the future.

By Jodi Torpey
A Colorado Master Gardener

Four Ways to Celebrate National Pollinator Week

Today’s the official start of summer and it coincides with another important annual event — National Pollinator Week. From June 20 through June 28, agencies, organizations, companies and ordinary gardeners bring attention to ways to help build healthy environments for bees, butterflies, birds, bats and other vital pollinators.

Here are four ways to celebrate pollinators this week. Please add your ideas to the list:

Million Pollinator Garden Challenge1. Register your garden on the National Pollinator Garden Network.

Become one in a million by registering your pollinator-friendly garden as part of the Million Pollinator Garden Challenge. The goal of the challenge is to register 1,000,000 public and private gardens and landscapes that give pollinators what they need: nesting sites and plants that provide pollen and nectar.

Pollinator Friendly Jacket Image2. Learn more about pollinators.

There are many free pollinator guides available if you need help deciding which plants give the biggest bang for pollinators. There’s also a new book written by a gardener for gardeners. Pollinator Friendly Gardening by Rhonda Fleming Hayes explains that no matter the size of your garden, there are dozens of good plants for helping pollinators. Her detailed plant lists simplify selecting flowers, herbs, vines, shrubs and trees.

3. Become a Habitat Hero.

Encourage more feathered friends to gather in your landscape through the Habitat Heroes program with Audubon Rockies. Apply to have your landscape recognized as a Habitat Hero wildscape. Some of the basics include planting bird-friendly native and regionally-adapted plants, reducing herbicide and pesticide use, and controlling invasive plants.

Pollinator Bee4. Plant zinnias.

A single packet of zinnia seeds will give you a summer full of color and plenty of lovely nectar-filled landing pads for bees and butterflies. Zinnias are some of the easiest annual flowers to grow whether in garden beds or containers on the patio, balcony or deck.

Please keep pollinators in mind and let’s work together to create a lot of buzz during National Pollinator Week!

By Jodi Torpey
A Denver master gardener

 

Big Harvests from Baby Vegetables

Up until a few years ago, small-space vegetable gardeners had a limited number of choices when it came to growing patio-size fruits and vegetables. Now, thanks to creative plant breeders and forward-thinking seed companies, there are dozens of small-sized fruits and vegetables meant for container planting.

Baby vegetables typically grow pint-sized produce on smaller-than-usual plants. The miniatures look just like the full-size options and retain all the same flavor, but because they’re smaller, they can be harvested and enjoyed earlier.

When shopping around, look for clues in the plant names like tiny, little, miniature, dwarf, bush-type, personal-sized or baby.

This season I had fun experimenting with three new vegetable plants especially bred to grow in containers or small-space gardens. Each grew especially well and produced a surprising number of beautiful and delicious fruits.

If you’re looking for some new container vegetables to grow next season—or to recommend to other gardeners who lack large vegetable-growing spaces—you might like to give these a try:

little bites cherry tomatoLitt’l Bites cherry tomato

Litt’l Bites is a small-size plant that’s perfect for hanging baskets. These were easy to start from seed (about 6-8 weeks before the last average frost date) and transplant into containers when weather warms. The plant grows quickly and sends out sprays of tasty tomatoes that cascade over the edge of a hanging basket or tall container. The tomatoes are ready to pick in 65 days and the plant keeps producing through the season. I planted nasturtiums with the tomatoes for added appeal.

Little prince baby eggplantLittle Prince container eggplant

Get a head start with these eggplants by planting Little Prince seeds indoors about 8-10 weeks before the last average frost. When transplanted into large patio containers, the plants grew two feet tall and produced adorable eggplants in 65 days. It seemed like there were always a handful or two to pick, and the plants kept producing all season. Little Prince would be a nice addition to an edible landscape because the plants feature green fuzzy leaves and nice lavender flowers. Harvest the fruits while they’re glossy to keep the flesh seedless and sweet.

baby butternut squashBaby Honeynut winter squash

As soon as night-time temperatures are 50-55 degrees, plant these little personal-size butternut squash seeds outside. The long vines grew well on a trellis placed in a large container. Each squash is about 4-5 inches long and weighs about 1 pound. Warm fall weather helps the fruit reach the 110-day mark for fruits to turn from green to tan and develop a hard outer shell. Wait for the first frost for vines to die, then clip the fruit, leaving a long stem for winter storage. These small winter squashes have a dark orange interior with an exceptionally sweet flavor.

By Jodi Torpey
Denver 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.

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!

Balcony Gardening – Green Walls

First it was “Green Roofs” now it is “Green Walls” or Living Walls.   You can create an outdoor Green Wall on your balcony.

a couple of trellis, anchored in a pot of dirt against one of your balcony walls. Depending on the amount of light you could grow flowering vines in the summer then plant peas in early spring.

metal shelving or a bookcase against the wall with planters on each shelf.  If your balcony is shady your “wall” can be made up of indoor plants – philodendron or other trailing plants.

– there are more sophisticated systems of hanging Green Wall “pockets” that look kind of like a magazine rack or sets of pots that can be attached to a wall in rows.   You could have edible plants like herbs and lettuce which require very little soil.  An internet search on green wall gardens will show you many options. 

As always, weight, water and building rules remain considerations for any system attached to the wall.  Ask before you invest.

Visit a local green wall.   “July Walking Tour – Sensory Garden’s Green Wall” by Angie Andrade Foster, Senior Horticulturist, Denver Botanic Gardens.

Colorado State University has a residence hall with an indoor green wall.  It is the Pavilion at Laurel Village.   An internet search will yield a variety of stories and photos.

Send me a comment and let me know where you find other indoor or outdoor Green Walls in Denver.

Balcony Gardening – Succulent Gardens

The Summer Solstice is past, Fourth of July is coming up. What if you forgot to water the flowers, the vegetable plants did not get enough sun and then it hailed!

Denver Botanic Gardens - Succulent Garden

Denver Botanic Gardens – Succulent Garden

There is a succulent garden for all budgets and all spaces:

–  buy individual cactus and arrange the pots on a tray a quick solution and many can become house plants at summer’s end.

– many garden centers have succulent gardens ready for purchase, ask how to care for them

–  buy annual or perennial rock garden plants and create your own using a shallow container, cactus type potting soil and gravel

– Winter-hardy cactus could be an option for your balcony

Plant Select Petites  has “Garden Treasures for Small Spaces” and a lot of suggestions for plants, planting and maintenance.

Pay attention to where you buy your plants.  If they were indoors they will do best  in a shady location.  If they were outside in full sun they will enjoy a sunny balcony.

If a cactus or succulent looked sunburned that is very possible if it was too much sun too soon.  Put your succulent garden in a part sun, part shade location to begin.  Even a cactus can get sunburned.       

 When in doubt – don’t water.  Too much water will cause the roots to rot and the damage is hard to spot until it is too late.  (I’ve had succulents surprise me by just falling over!)

The internet has lots of information on succulent gardens.  If all this sounds like a better project for next month, then a few pots of red, white and blue petunias is a cheerful alternative.  Enjoy!

Balcony Gardening – Soil, Light and Plants

French Tarragon 1 year after planting in container

French Tarragon 1 year after planting in container.

Time to plant your balcony garden

Soil for container plants is easy to find. Don’t use “Top Soil”. It is likely to be mostly clay and too heavy for your balcony use. Potting soil (with or without time release fertilizer) will be just fine.

If you buy plants – fit them tightly into the pot.  You will have a nice showy pot and it is unlikely that they will outgrow the space over the summer.  If you plant seeds, don’t put the pot in full sun.  Keep seeds moist until they germinate by covering the pot with plastic wrap to keep the soil from drying out and

How much sun your balcony gets will determine your choice of plants.   Don’t forget reflected light from nearby buildings.  Your balcony may receive direct sun only in the morning, but also receive reflected light from the building next door in late afternoon.  This article lists 5 ways to categorize sun and shade for choosing plants (about 2/3 down into this article is the list). More information is there is you want the details. 

Vegetables:  most container vegetables like full sun but may need shade from reflected afternoon light or direct afternoon sun.  Vegetables need to be checked every day to see if they need water – many will, especially when putting on fruit.   Recommended Container Vegetables are listed by type and by name.

Herbs:  Basil is a standard and will probably need water daily in hot weather.  Try cilantro or a chocolate mint plant.  Most perennial herbs grow well in containers and may survive the winter.  Good choices are  French Tarragon, any of the Thyme varieties, Winter Savory, Chives.  Here is more information about Growing Herbs in Containers.

Flowers:  If you would like to screen the view from your balcony – plant tall annuals.   An 8 inch deep pot is best.  All of these grow easily from seed:  sunflowers, cosmos, morning-glory (add a trellis for it to climb).  Amaranth is a grain ( not very edible) and grows 6 feet tall!  Look for the burgundy variety.

How to Grow Blueberries in Colorado Gardens

BlueberriesColorado gardeners who fall in love with the idea of growing their own blueberries may be disappointed with the results. There just isn’t enough room on a planting tag for all the information they need.

Even if they carefully follow the basic planting instructions, blueberries need much more than “Full sun, acidic soil (incorporate peat moss or organic matter into soil), good drainage, fertilize in early spring, moderate watering.”

That’s because blueberry shrubs arrive in Colorado from growers in the northeast or the northwest where conditions are ideal for growing the plants. The climate on each of those coasts is significantly different from Colorado’s land-locked and semi-arid climate.

The two main challenges the blueberry planting tags don’t cover are the soil pH problems and the way winter dries out plants in our region.

Both of these problems can be solved, but it takes extra effort.

Thanks to CSU Extension blueberry experiments, gardeners have a proven blueprint for blueberry success.

The experiments, conducted by Joel Reich while he was a CSU Extension Horticulturist, are detailed in a one-hour webinar recorded in August 2012 called Blueberries for Colorado Gardens.

Anyone with online access can view the free program to learn all about the best blueberry varieties to plant, where to find them, how to plant and fertilize them, best practices for winter protection and how to keep birds and deer from getting to the juicy fruits before gardeners can enjoy them.

The blueberries growing in CSU’s trial gardens in Longmont show that if gardeners plant in sphagnum peat moss and provide special winter protection, they can enjoy fresh blueberries season after season.

Joel grew blueberries in the trial garden for more than 16 seasons in the same bales of peat moss. He devised a fertility maintenance program with a special combination of acidic fertilizers to use on a May, June, July schedule.

Planting

Best practices for planting blueberries mean planting directly inside the sphagnum peat moss bales. The bags are opened only part way to help retain moisture. Holes in the bottom of the bag provide drainage. Drip irrigation is important to make sure the soil stays consistently moist.

The bags are placed in trenches so they’re at grade level, but they could also be placed in a raised bed. Gardeners could grow plants in patio or balcony containers if they select the blueberries classified as “half-high.”  Plants growing in containers will need even more protection from wind in winter.

Protection

The key to providing winter protection is to prevent the damage caused by dry weather, low humidity and winds. It’s especially important to wrap or cover each plant so winter winds can’t suck the moisture out of the dormant buds.

The blueberry shrubs need to be wrapped in layers of burlap with the branches tied up and together. An alternative is to cover each plant with a trash barrel that’s weighted down.

By Jodi Torpey