Monthly Archives: July 2015

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.

What to do in the Garden in late July-Early August or (A Midsummer (Day’s) Dream)

We have all been entranced by the New Horizon spacecraft’s approach to the (dwarf) planet Pluto, watching the photographs emerge from the dark of space.  But if we turn our eyes down to the ground during the daylight of our own star/sun, our gardens now are in the full heat of sun and summer.  Our tasks for mid-July to mid-August turn from spring planting to growth, maintenance, and watering.


  • Watch the vegetable crops. Apply a balanced fertilizer (5-10-5) to long season crops, which are most of our typical summer vegetables.
  • Fertilize roses for the last time by mid-August.
  • Do you have hanging baskets? Feed them as you irrigate since frequent watering flushes fertilizer from containers.
  • If you have taken indoor plants outside for the summer, be sure to fertilize them.
  • When the harvest is finished, fertilize strawberry plants with a high nitrogen fertilizer (21-0-0).
  • Plant some cool weather crops (such as beets, escarole, kale, collards, lettuce, radish, turnip, chard, and spinach) for a fall harvest.


  • Do be aware that when the temperature is over 90o F, tomatoes and peppers won’t set fruit.
  • Iris need to be thinned about every three to four years, otherwise they will become crowded and will not bloom well. By mid-August, divide iris by cutting them apart and discarding old, large or diseased rhizomes.  Healthy rhizomes can be replanted or given away as pass-along plants.
  • Divide spring-blooming perennials (if needed) by mid-August.
  • After once-bearing raspberries and blackberries finish fruiting, cut the producing canes to the ground, the new season’s canes will produce berries next year.
  • Continue to dead-head annuals and perennials to keep new blossoms coming.
  • Start harvesting vegetables.


  • Try to keep the soil moisture consistent around tomato plants to prevent the fruit from cracking. (An inexpensive moisture meter is an invaluable aid to checking soil dampness.)
  • Check moisture levels around newly planted trees and shrubs. Again, water thoroughly if the soil is dry.
  • Keep about four inches of mulch around plantings and in garden beds to help retain moisture. Refresh or add new mulch to the garden as necessary.
  • Per CSU, “check the top and outer leaves of trees and shrubs for drought injury: brown or tan scorch on broad leaves and brown needles or dead tips on conifers. Check the bottom and inside leaves for over-watering: faded color between the veins and dropping leaves or needles. CSU Fact sheet 2.932 tells more about drought and over-watering.”
  • Water your lawn 2 to 2-1/4 inches per week through July, decreasing to 1 ¾-2 inches per week in August, if the weather is hot and dry.
  • Mow to keep the grass height 2 -1/2 to 3 inches.
  • Check hanging plants twice a day for dry soil and water as needed.

Now is the time to stroll through the garden, nurture the wonderful produce, and enjoy the perfume of our flowers.  Of course, there is always something to do in the garden, no matter what the season.  Happy gardening!

By Mary Beth Cooper, Denver County Master Gardener

Major source for this article is “Down to Earth in Denver”, an online CSU extension monthly calendar of gardening tasks.  The link is

Tomato Gardeners Need this App

Tomato MDOne of the best gardening investments I’ve made lately is buying the Tomato MD app available through the American Phytopathological Society. Master gardeners need this app, especially those who answer gardener’s questions at the farmers’ market, by phone or online.

The reasonable $2.99 price is worth every penny if you’ve ever been stumped by the question, “What’s wrong with my tomato plant?”

I don’t know about you, but tomato-growing questions are my most frequently asked question. It’s also a question that I’ve asked myself many times. The CSU fact sheet on Recognizing Tomato Problems is a good resource, but it’s less comprehensive than the Tomato MD app.

Tomato MD is an interactive resource that works with either Apple or Android devices. It’s easy to use and can help you pinpoint just about any tomato problem using the menu of plant diseases and insect problems.

The beauty of this app is that it can be used anytime, anywhere because you don’t need the Internet to access its features. Once you download it to your phone or tablet, you can take it with you into the garden or the CSU Master Gardener’s booth at farmers’ markets or any gardening event.

The app is a great resource for master gardeners. Home gardeners, garden center staff and even professional growers can benefit from this tomato-growing tool, too.

When you’re asked about a tomato issue, the app lets you search in three different ways:

Alphabetical listing of diseases and insects
Images of the 35 most common problems that affect tomato plants
Disease or insect damage characteristics

I’ve found it’s helpful to start by clicking on the photo gallery. That’s where you can choose the affected part of the plant, from leaf to flower, fruit, stem and roots. Select the affected area and then thumb through the images to find a photo match.

Tomato MD covers problems like alternaria stem canker, bacterial spot, blossom end rot, drought stress injury, tomato spotted wilt, early blight, late blight and plenty more. The rogue’s gallery of insects and mites includes tomato hornworms, tomato fruitworms, stink bugs and many of the other harmful insect pests.

Once you’ve identified the problem, the app gives you a menu of options for symptoms, causes and sources, other plant hosts, imitators, control options and additional help with diagnosis.

Much of the content for the Tomato MD app is from the American Phytopathological Society’s research and its two massive and expensive volumes called Tomato Health Management ($89) and Compendium of Tomato Diseases and Pests ($99). I’ve wanted to add these books to my library, but the cost was prohibitive.

At $2.99 Tomato MD solves that tomato problem, too.

By Jodi Torpey, a Denver Master Gardener

Aspen Suckers – Persistence Pays!

For many years, my property line was bordered by a small patch of aspen trees planted by a well-meaning neighbor. They were lovely for a few years but despite good care, things began to change – fungal diseases, insects and visible cankers, anemic fall color, as well as “gifts” in the form of aspen suckers peppered both lawns. While I’m not a lawn zealot, these suckers can rather quickly turn into a mini grove of trees as aspens reproduce by sending up shoots from the root of the mother tree. Suckering sometimes indicate that mom is on the decline, which in this case was true.

In early spring 2014, the owners decided the aspens were beyond saving and they removed the ten year old trees. With the trees gone, the  suckers continued to sprout with a vengeance, as the remaining underground root stock tried to offer us replacement aspens.

To win this battle, before every mowing (and sometimes more often) we diligently removed the tender new shoots and their roots by hand and dabbed freshly cut larger suckers with a product recommended by our local garden center (look for active ingredient Ethyl 1 Napthaleneacetate). Ideally, we would have tackled this without chemicals, but in this case, we were advised to go this route. Additionally, we aerated the lawn and over-seeded the grass to make it healthier and thicker, hence more difficult for suckers to emerge. To discourage sucker production, we were vigilant about not over watering.

I am proud to say that this year our persistence has paid off. We’ve not had a single sneaky shoot in the lawn or adjacent garden bed, even with this year’s abundant moisture. The remaining root stock appears to have died out, so (fingers crossed) the suckers are gone for good. For more info on reducing tree  suckers and seedlings:

Our experience is very common. Aspens are beautiful in the mountains, but ill-suited for the urban landscape. At lower elevations they are frequently disease prone, insect plagued and short lived. Since they thrive in moist, well-drained and slightly acidic soil and at higher altitudes, the Front Range soil, which is predominately compacted, alkaline and clay, is just not ideal.  If you already have aspens on your property, here is information which may help you keep them at their best:

If you are thinking of adding trees to your front range landscape, check out this list of tree recommendations from Colorado State University

Written by Linda McDonnell, a Denver County Master Gardener since 2013

Colorful Planters for the 4th of July!

If you are like me, you enjoy celebrating the 4th of July.  I like to decorate the outside of my house with flags and other patriotic decorations.  My favorite way to decorate my back patio is to use combinations of red, white and blue flowering plants in a container.

Here are a couple of my favorite combinations for a fun 4th of July planter:


Red Geranuims

White Alyssum

Planter #2:

Blue Ageratum

White Petunias

Red Salvia

When planting your new container, don’t forget to use a good quality potting soil.  After planting, water the container thoroughly.  Also consider adding a slow release fertilizer to the soil.

Have a great 4th of July weekend!

By Merrill Kingsbury