Episode 40 – Watering advice, a game-changing spirea, native ferns, and the “Chelsea Chop”

Ground Breaking Banter - Rick

Are your landscape plants happy with how you water them? Let’s “test the waters” and see if our theories “hold water.” Even areas not familiar with water restrictions have seen them enforced in the past few years. Take, for example, the UK last summer, where the nation’s highest-ever temperature of 40.3C (104.5F) was recorded in Coningsby in Lincolnshire on July 19, 2022. Drought (since relieved, they learned a lot last year 2022) caused municipalities to engage a three-year “hosepipe ban.”

They can drive you crazy, those kinky hoses, cheap sprinklers, and pistol grip nozzle sprayers. Pistol grip nozzles are meant to wash cars, not water plants.
While drip or trickle hoses make sense, those sprinklers with two settings drip and monsoon are the worst. Got a hose or watering rant of your own? Send us your thoughts!

We can all thank Jan Van Der Heyden for inventing the hose.

As it relates to hot dry weather and watering:

  • Mulch makes a huge difference, as I discovered at the Bartlett Tree Research Laboratory in Charlotte, North Carolina one July. We focused on the temperature swings (minimum to maximum) as well as average soil temperatures during a given period in the heat of the summer when tree stress is at its greatest. The results for a 30-day window in mid-summer showed that forest leaf debris worked the best for keeping the average soil temperature cool and keeping the min-max fluctuations to within 5 degrees, with wood chip mulch being a close second at a 9-degree fluctuation. The temperature fluctuations for turf grass and bare soil were over 21 degrees during the day/night cycle and the concrete in full sun rose and fell by over 68 degrees! Here is an example of a typical daily temperature fluctuation from the plot in July
  • Rick’s water-wise advice: dig some holes. Fill with water. Watch what happens – it’s a great way to figure out how well your soil drains.
  • Time of day watering. Avoid watering during the heat of the day, as a large share of it will evaporate via wind and sun.
  • Keep on top of weeding.  “Like all plants, weeds need water to survive. Keep your beds weed-free to ensure they don’t deprive the plants you want to grow of hydration.
  • Intentionally group plants together that have similar water and sun exposure needs. You’re responsible for planting it right in the first place with the right plant in the right place.  Familiarize yourself with plants that have characteristics making them drought tolerant. Waxy small needles or leaves? For example, think of annuals like moss rose or gomphrena in the sun or for dry shade wax begonias. Perennials like yarrow (Achillea sp.)  ornamental grasses, sedums, daylily or butterfly weed. Shrubs like potentilla or buddleia.  
  • Prioritising improving the health of your soil now by adding organic matter like compost and manure could reduce the need for watering.
  • You will see advice to use plants with grey-green or silver foliage as they reflect light and tend to be more drought tolerant.

Why: When the weather gets hot and dry, you want a plant that can continue to perform without a lot of pampering, so what better plant to put on trial today than the incredibly durable, incredibly beautiful Double Play Doozie® reblooming spirea. While, like all trees, shrubs, and perennials, it will need regular watering for the first season or two after it is planted, this unique spirea will be able to tolerate some seriously challenging conditions once it gets established. That’s actually true of all spirea, but when it comes to this perpetually popular landscape and garden plant, you can’t do better than Double Play Doozie from Proven Winners ColorChoice Shrubs. That’s because unlike other spirea, it doesn’t just bloom once in early summer – it continues to bloom all through the summer and into fall, with a continuous supply of pink-red flowers. In fact, it’s rarely without them! That’s because Double Play Doozie spirea does not produce seed. This trait kind of tricks the plant into acting like its flowers have not served their reproductive purpose, so it just keeps trying – and that means you keep seeing fresh flowers. Unlike other reblooming shrubs, the fresh flowers emerge right alongside the fading ones – no waiting between waves of blooms.
Double Play Doozie spirea naturally grows as a tidy mound. When the foliage emerges in spring, it’s an eye-catching red-burgundy color for extra color (that’s the “Double Play” part). It’s fabulous used on its own and even better planted as a low hedge or mass planting.

Who: Double Play Doozie spirea is another high-performance new variety from the always innovative Dr. Tom Ranney at North Carolina State University. 

How to grow: Like all spirea, Double Play Doozie is a pretty laid back, forgiving plant. It can take full to part sun, and thrives in any well-drained soil. No pruning is required to maintain its tidy habit, but if you want to prune it, do so after its first flowering in early summer. This is likely to delay the subsequent blooming, though. Deadheading is not required for continuous blooms, but you may find that you prefer the look of the plant if it is given a light trim when the first wave of flowers fade, though this isn’t necessary. As with most reblooming plants, regular fertilizing is beneficial – the extra nutrients will boost blooming. Applying fertilizer once a month from early spring through late July is sufficient. 

If you’d like to add Double Play Doozie spirea – or any of the 320+ Proven Winners ColorChoice Shrubs – to your garden or landscape, you’ll find a list of local retailers here

Gardening Mail Bag - Stacey

If you want to stick strictly to native ferns, the following should be quite tolerant of the shade and well-drained soil: broad beech fern (Phegopteris hexagonoptera), common wood ferns (Dryopteris carthusiana), Christmas fern (Polystichum acrostichoides), and Northern lady fern (Athryium filix-femina). If you’re willing to extend to ferns native to the US, I have found that the Dixie wood fern, Dryopteris x australis, does amazing well in my very dry, sandy soil, contributing the drama of ostrich fern (Matteucia struthiopteris) without the high water needs. You can find a nice list of Michigan native ferns here for more suggestions, though you may find that many of them have water needs greater than your site is able to accommodate. 

You can do all the normal things we recommend to mitigate powdery mildew: plant in full sun, make sure the plant has good air circulation by keeping it properly spaced from other plants and structures, and avoid overhead watering. Your peony rings also help a lot by keeping foliage off the ground and allowing air flow to the whole plant. However, even if you do all the best practices, the simple fact of the matter is that peonies just get powdery mildew. To our knowledge, there are no herbaceous peonies out there that are resistant, and I can’t recall any not ending up with at least some powdery by the end of the season. So, don’t blame yourself, and take comfort in the fact that while it may be a bit unsightly, powdery mildew does not harm or set back the plant at all. One last bit of advice: come fall, when the plant is dormant, cut off and discard all of the brown foliage.  

There’s no way around this: cucumber beetles are one of the most destructive and hardest to control pests. Don’t be deceived by their name: as Kelly’s question shows, though they do love preying on cucumber plants and their relatives like squash, they eat a huge variety of vegetables and ornamental plants. And their damage on flowers is particularly unsightly: rough holes, staining, premature fading and death. Short of using chemical controls, there’s unfortunately no silver bullet. But there are a couple of things you can do to perhaps minimize their presence:
– Control weeds. They like to hang out in weedy areas when they aren’t feeding, so if you (or a neighbor) have weedy areas that could be managed, that may help.
– Stop growing cucumbers or members of the cucumber family, like squash. This will attract them, and they may get curious and explore other plants in your yard.
– Or, do the opposite: grow cucumbers or squash as a “trap crop” that you do treat with insecticide. This would not be for human consumption, only to lure the cucumber beetles to one area and then use chemicals to manage them.
– Mulch. Finally, an easy one! Mulch helps a lot because the cucumber beetles lay their eggs in soil cracks near potential host plants. By covering up the soil, you reduce the egg-laying sites (but be aware, they can also lay eggs at the base of the plant as well). 
– Finally, consider biological controls like beneficial nemarodes, lacewings, assassin bugs, or even ladybugs. Here are some good biological solutions for cucumber beetles

Do you have a question for us? We’re happy to help! E-mail us or use the contact tab above.

Branching News - Rick

  • Last week one of our YouTube viewers brought up the topic of “The Chelsea Chop.” The “Chelsea Chop” is a pruning method where you cut back taller perennials in Spring by one-half to one-third of their height. The result is stronger and sturdier stems as well as a more compact plant. It will help prevent certain perennials from leaning, flopping, or tipping over and provide an overall nicer appearance. Although this is a standard pruning method, the name “Chelsea Chop” originates from England’s Chelsea Flower Show, which coincides when a gardener should prune their perennials in England’s climate. (This year’s show was Monday May 22, 2023 – Sat, May 27, 2023) The best time to do the Chelsea Chop is about 4-6 weeks before blooming, or when the plant has reached 1/2-2/3 of it’s expected overall height. For most plants, this is between mid-spring and the start of summer. Plants like upright sedum, helianthus, Joe Pye weed, phlox, heliopsis, monarda, Shasta daisy, echinacea and rudbeckia can all potentially benefit from a Chelsea chop.  
  • A Washington State University-led study revealed plants can sense when something touches them and when it is let go. Michael Knoblauch, WSU biological sciences professor and senior author of the study in the journal Nature Plants, and his colleagues saw many complex responses depending on the force and duration of the touch, however, the difference between touch and removal was clear. When researchers applied 30 seconds of touch to a plant cell, they saw slow waves of calcium ions, called cytosolic calcium. These slow waves travel from the cell through other plant cells which last around three to five minutes. However, removal of touch from a plant cell showed an instant set of faster waves that disappeared within a minute. 
  • A study, published in the Journal of the Academy of Nutrition and Dietetics, looked at data collected from over 146,000 American adults over the age of 65. The participants were broken down into three groups — gardeners (older adults who garden), exercisers (ones who engage in other physical activities besides gardening) and non-exercisers (sedentary individuals). Gardeners reported spending more time staying physically active compared to exercisers, and they were able to meet the recommended 150 minutes of aerobic activity per week with just gardening alone.
    Compared to sedentary individuals, gardeners reported significantly lower odds of cardiovascular disease, stroke, heart attack, high cholesterol, high blood pressure and even diabetes. They were also more likely to meet their fruit and veggie quota for the day (truly reaping the fruits of their labor!).