On Giving Plant Advice

3/21/2021

It's that time of the year when social media is flooded with folks posting images of their landscapes -- often trouble spots like under large shade trees, dry corners, and wet low spots -- asking for plants that will do well in those areas. Before you rush to offer advice, try to both educate and challenge the online community to get us closer to true success in such spaces. Usually, people asking for plant ideas are relatively inexperienced and just starting out, so if we suggest the wrong plant they may quickly get discouraged. What is the wrong plant?

One that spreads too easily or takes over.
A plant that withers and dies.
A plant that just sits there, never growing, just subsisting.

And why do these things happen? Because we haven't asked the good questions about the site or the gardener in order to make the most informed suggestions for long-term success and empowerment. Parameters we need to consider:

Ecoregion (not USDA hardiness zone); zipcode works.
Amount of sunlight and at what time of day (sunlight has different UV rays at different times of day, some more powerful than others).
Slope and drainage (on and off site).
Soil type (even a soil test)
Current vegetation (are there weeds that need treating, and / or what are the plants the new ones will need to mesh with).
How the space will be used by humans.
The aesthetic goal (just cover the ground, block a view, prim and proper, wild...).
Management style of the gardener (hands off, helicopter parent...).
Budget

There are more we could add but this is enough for now. Can you see why these are all important factors in creating a successful garden of any size? I know we just want to offer quick advice that makes gardening seem simple, but sometimes simple can lead to unnecessarily hard when we don't stop to think and plan a little bit before exploring plants, plant communities, design, and management. My biggest fear is that the social media advice I run across -- advice that is well intentioned but often not applicable -- will ultimately frustrate gardeners. But maybe asking these questions will, too, making the process seem more like those paragraph-long math problems from junior high. Still, they are necessary parameters to consider and will save us headaches over the long term. So ask the tough questions and get us thinking better.

Culver's root, Veronicastrum virginicum, medium to moist soils in full sun (gets 4-6' tall and slowly spreads as a clump)

3 Comments

James McGee

3/21/2021 09:28:37 pm

The neighborhood where I live has a lot of deciduous trees. This time of year, I am out with a rake and leaf vacuum removing the leaves that are smothering plants in my garden. I am starting to wish I had taken into consideration where the leaves accumulate when I planned my garden. Of course, the fact that a garden is present with dead stems in the fall might be the main reason the leaves are accumulating in spots.

I do burn some of my gardens in fall which gets rid of the dead stems and leaves. However, I don’t burn the gardens where I have plants that might be negatively impacted by fire. These include gardens with Heucheras, woodland iris, shrubs, and certain dryland plants that probably would not do well after fire like cactus.

The gardens that I don’t burn require a lot of cleanup in the spring. The flip side is the leaves help protect some plants through the winter. An example of plants that benefit from a protective layer of leaves includes succulents, like sedum, but really anything that does not die back completely under the ground.

Do you take leaf accumulation into consideration when you design a garden?

Cynthia Abbott

4/6/2021 08:29:41 am

Where you possibly can, leaving the leaves in place provides habitat for fireflies and many other animals who spend all or part of their lives in leaf litter. Fireflies, for example, are predatory larvae (that look like hard shelled, pointy caterpillars) for several years before pupating and changing into adults. Many of the big silk moths spend the winter and some part of the spring (even summer) in cocoons disguised in leaves in the leaf litter.

Other benefits of leaf litter include forage for birds, who love to scrape through leaves finding tidbits and juicy morsels to eat. (Ever watch a brown thrasher or towhee at work?!). The leaves also soften rainfall on the soil surface, decrease moisture evaporation from the soil, and enrich the soil as they decompose.

In related lines, leaving at least some of your plant stalks can be beneficial, too. Many of our native bees use hollow plant stems as nesting sites, making a series of little cells which they fill with pollen and nectar, then lay an egg on the food and seal. These native bees only have one generation each year, timed to coincide with whatever plant(s) they use for food, so leaving stems can make or break their populations locally.

If the leaf cover seems heavy, I just generally move some of the leaves away from the plant crowns as they are emerging in the spring - and often even that isn't necessary.

It's so much fun to see how many wonderful birds and insects are enjoying my gardens along with me since I started changing my gardening habits in this way!

James McGee

4/6/2021 09:43:44 am

I don’t discard the leaves I rake or vacuum up from my gardens. I just move them to under shrubs where I don’t have anything growing. In fall when I rake my lawn, I do chop the leaves up with a mower before using them to mulch my gardens. I must do this, otherwise they blow off the gardens back onto my lawn or onto my neighbor’s property. The neighbors tend to not appreciate having my leaves blow onto their lawns.

The conundrum about the leaves is the location where I live was historically prairie. Now it is old suburbs with lots of mature trees. A lot of the native prairie plants are really small and get eliminated by a smothering layer of leaf cover. Even some woodland plants are restricted to drier slopes where the leaves tend to blow away. If I am going to grow plants that were originally present where my property is located then the leaves need to be burned off, chopped up, or removed.

Some areas tend to collect more leaves than others. I am wishing I had put more thought into where leaves collect before planting. However, once an area is planted then the stems tend to trap leaves. This is a no-win situation for a garden designer. The leaves are going to have to be managed some way if plants that were historically native to the location are going to be grown.

The Deep Middle