Summer Garden Checklist

Kansas summers can discourage even the hardiest gardeners. However, taking time to manage your garden now will help your garden later. Here’s my Summer Garden Checklist for the Kansas gardener.

Control Warm Season Weeds

Summer brings with it a new set of weeds to control. Hot weather germinates summer annuals like crabgrass, foxtail. Nutsedge and other weeds invade your lawn and landscape as well. Manage weeds using nonchemical methods such as cultivation, hand weeding, or mowing; use toxic chemicals as a last resort. 

Mowing regularly and occasionally edging along sidewalks and walkways is needed to ensure your lawn is not overrun with weeds. In a landscaped bed, hand pull any of these weeds, especially if they have seed heads.  It is so important to not let these weeds go to seed. Stay vigilant even though the summer heat tries to squash your enthusiasm. A little extra effort now will make your garden better this fall and into next year. 

Crabgrass in tree mulch ring controlled with roundup: one treatment should clean up the mulched area and keep it weed free the rest of the season.

Be Water Wise

To reduce evaporation, water when temperatures are cooler and air is still, usually in the early morning. Water deeply to moisten the root zone, but infrequently. About an inch of water each week is a good rule of thumb!  If you have invested in container plants, they will need daily watering, as soil in pots can dry out quickly and damage plant roots on hot summer days.  Each of our gardens have indicator plants that show stress first, let these plants be your guide as when to water.  For new planting started this spring, water when the top one to two inches of soil is dry.  Remember it takes three to five years for sustaining roots systems to develop for most native plants.  Supplemental watering is necessary to encourage growth and root development in these young plants. 

We use pressure compensating 1/2 inch soaker hoses to efficiently water trees, shrubs and a few flower beds. Each emitter puts out 1 gallon of water per hour.

Prepare for seeding

If you are wanting to establish native prairie plants from seed, now is a great time to prepare your area.  Mow your area short (1-2 inches). Control perennial weeds such as bindweed or Bermuda grass by carefully spraying the area with Roundup. It will take several applications to get these problematic weeds under control. If you can see soil, tillage is not necessary. If you can’t see soil, till lightly to expose some bare soil. Remember, each time you till, you bring up more weed seeds, so tread lightly. 

Measure your area and order a seed mixture that matches your site. A good seed mix ratio of wildflower to grass is 70% wildflowers to 30% grasses. Grasses tend to dominate over time, so this ratio will give the wildflowers a good start. We typically spread seed in November and December after the soil temperature has dropped enough to discourage germination. The natural freeze/thaw of the ground will work the seeds down into the soil to the proper depth for germination next spring. 

This is the seed mix we established along our newly renovated path.
Sidewalk edge planting: We mixed some sand with the seed mix to make it easier to distribute. We then let the natural freeze/thaw of the soil plant the seed for us through the winter. Germination occurred the following spring when soil temperatures rose above 60 degrees.

Trim

Now is a great time to trim back perennials that have become unruly. Perennial and grasses that are encroaching sidewalks, paths, and structures can be sheared back to size. If this is a problem every year, you may consider moving the taller plants to another spot. Plants can be divided next February or March before they start to actively grow. 

Low hanging branches from trees can also be pruned. It is getting late in the season to do much pruning on shrubs. New growth may not have enough time to get hardened off before cooler/colder weather.  If a branch or shoot is in the way, then prune it, but prune sooner rather than later. If you can wait until the shrub goes dormant this fall, then wait. 

As a general rule, early spring flowering shrubs such as forsythia, lilac and spirea should be pruned right after they are done blooming since they bloom on the previous year’s growth. Pruning right after blooming will allow the shrub to grow and develop a new set of buds for the next spring. 

A large compass plant that needs to be trimmed away from the path.

Finally, remember “WHY” you are gardening; creating habitat, conserving water, aesthetics, attracting pollinators, attracting birds and other wildlife or curb appeal. Let your “WHY” reinvigorate you to take care of a few extra tasks that will give your landscape a boost. Don’t sweat the small stuff and don’t forget to step back to enjoy what you are trying to create. If it is all work and no enjoyment, then what is the point.

Pale purple coneflower with a common buckeye butterfly. Fun to watch!

Five Elegant Perennials for the Summer Landscape

Lately, I have been watching old Western films.  John Wayne always looks so calm and collected.  He never sweats, even though he is wearing five layers of clothing.  Have you ever wondered why they wear so much when it is so hot?

Right now, I wish I had a sprinkler to run through or a bucket of ice water to dump on myself.  Those movie characters who ride through the desert unscathed remind me of some tough plants blooming right now in the arboretum.  It is a true testament to the toughness of some perennials that thrive in adverse conditions.

Try these sun-loving perennials – you will be rewarded year after year by these resilient plants:


Letterman’s Ironplant-Vernonia lettermanii ‘Iron Butterfly’

While walking through the gardens this morning, I noticed the vibrant purple blooms of this iron-clad wildflower.  We should be tooting the horn for more natives like these.  The plants were alive with activity-like a pollinator magnet!  Each stem has slender leaves radiating outward, similar to Amsonia hubrichtii.  This is a more refined ironweed, but just as tenacious as the pasture type.  I use them in groupings with switch grass and goldenrods but they would be a nice addition to any landscape.

Vernonia Iron Butterfly

Photo taken at Dyck Arboretum of the Plains

 


Russian Sage-Perovskia atriplicifolia

On my recent trip to Denver, Russian Sage was ubiquitous.  That’s a fancy word for everywhere.  It was in the street medians, parks, store fronts, and in front of most homes, but for good reason.  The soft lavender blooms are eye-catching.  The cloud of colorful flowers above the finely textured aromatic foliage is a wonderful combination.  Did I mention that Russian Sage is tough?  It shines in any full to part sun location.  It can survive drought conditions, but appreciates weekly watering.  They are best displayed in mass plantings or with native grasses.

Russian Sage-Photo Courtesy of Walters Gardens, Inc.

Photo courtesy of Walters Gardens

 


Button Blazing Star-Liatris aspera

Blazing stars have put on quite a show this year and button blazing star is no exception.  It is in full bloom right now in 100 degree heat and loving it.  The entire plant matures to 3′ in height, but the real show is the purple button flowers that develop along the stem.  It is happiest in medium to dry soil conditions and will become unhappy with too much moisture.  Pollinators flock to it, including butterflies, hummingbirds, and bees.  Plant them in mass, 8-12 inches apart for the ultimate display.  I like to integrate several grasses like Little Bluestem or switch grass to give interest later in the season.

Liatris aspera

Photo taken at Dyck Arboretum of the Plains

 


Hummingbird Mint- Agastache ‘Blue Boa’

This plant has been one of my biggest surprises over the last several years.  It is almost always in bloom.  It loves the heat and humidity.  The deep violet-blue blooms lure many different pollinators and ‘Blue boa’ requires very little care once established in a medium to dry location.  If you want to help the pollinators, try a few in your landscape. You will be surprised by them, too.

Agastache Blue Boa-Photo Courtesy of Terra Nova Nurseries

Photo courtesy of Terra Nova Nurseries

 


Aromatic Aster-Aster oblongifolius ‘October Skies’

We have been growing this great form of our native aromatic aster for several years.  It is not rambunctious in the landscape.  In fact, it develops into a nice bush that is covered with glowing lavender flowers.  When the whole plant is in bloom it looks like a mum on steroids.  Flowers begin to open in late September and last into October.  During the warm days of autumn, pollinators congregate on these beauties, seeking to collect the last pollen of the season.  We have used them in borders and native groupings with ornamental grasses.

Aster October Skies

Photo taken at Dyck Arboretum of the Plains

 

Notice the theme?  They all have lavender blooms.  These are a few plants that are doing well in the arboretum.  What plants have you had success with this year?