Hellstrip Gardening: Full Sun? No Sweat.

Some people have gardens abundant in gorgeous mature trees, rich soil, and even pockets of direct sun. What plants would complain? But at the other end of the spectrum, there are gardeners in midsummer that are covered in sweat, shaking their heads when their plants struggle just to transpire. We may have a long growing season, but our summer sun is intense here in the southeast. Extremes ravage photogenic foliage into tatters. Perhaps we have a south or west facing bed, with nothing to cast shade, sunup to sundown. Nearby, there may even be a pebble walkway or lovely (but heat trapping) garden boulders you so carefully placed. Chances are your plants here are waiting for fall with the same intensity that you rush from car door to front door in late July.

If these struggles sound familiar, congratulations! You have the conditions for which only a desperate shade-gardener would pay. But don’t let plant grief weigh too heavy on your shoulders. There are a number of plants that might be featured on magazine covers, but look just as spectacular (and in some cases more so!) in the worst of conditions. For our purposes we can think of a hell-strips as the perfectly horrendous trifecta of critically poor soil, blistering sun, and severe drainage issues (either too much or too little).

Dr. Elaine Ingham writes in “Managing Soil Health” that having compacted soil is a compounded problem. She explains that because compacted soils only house anaerobic bacteria (those requiring little to no oxygen), nothing can grow. The anaerobic soil microorganisms exude toxins downright poisonous to plants, Ingham explains. In fact, tests have shown plant roots die as they come into contact with these toxins. They literally fry at their ends! So, what does she recommend we do? Make the soil more hospitable to beneficial microorganism by integrating compost. Lots and lots of compost. (Side note: Ingham recommends against tilling as it can create a hard pan deeper down, preventing any plants from forming roots deep enough to allow them to qualify as drought tolerant – an important quality to nurture in the hell-strip!

So, what if you want to get planting right away? Since beneficial microorganisms take time to loosen the soil, what – if anything – can we do to speed up the process if tilling is no option? The answer here lies in the plants we use! And lucky for us, many of the plants listed here also handle sandy and gravely well drained leaner soils. Although in the south, where compost decomposes and washes out more quickly than most of it can be incorporated as humus, it is still possible for it to help us build soil structure beneath the surface. Sadly, the soil here will never be our dream soil and this is why we shake our heads come July.

The first place to start is to incorporate plants in the Legume/pea family. Ingham recommends making as much as 25% of your planting scheme from this family. Not only do these plants repair soil by fixing nitrogen, the pea family also has many members that build deep taproots and withstand drought, while drinking up the sun. Three for one! Some examples include: our own native wisteria (Wisteria frutescens), Baptisia cvs, our native lead plant (Amorpha canascens), and our native wild clover (Dalea sp.).

The next place to look would be incorporating design element of structure. There are always some smaller shrubs to consider in these difficult places. Black Chokeberry (Aronia melanocarpa), and butterfly magnet and host plant New Jersey Tea (Ceanothus americanus) are both drought tolerant natives that take the harshest of soils and rocky situations as well as they take heavy slow draining clay. Unlike other natives that claim drought tolerance, these shrubs deliver even in the worst years.

Other great soil builders would be anything that breaks up compacted areas using its roots, and/or by the beneficials they attract at any stage in their development. Yarrow has long had a reputation for building soils and handles drought dramatically well. In fact, in seems to perform better in less rich soil, with stems that flop less.

A second category of soil builders would be considered “mulchers”. These are plants that provide a large heavy leaf. Wild quinine (Parthenium integrifolium) is my top pick here, along with another native Rudbeckia maxima. The tall rudbeckia produces gorgeous glaucus foliage that keeps an evergreen appearance in mild winters. If that isn’t enough to sell the plant, their seeds make great bird food, and their new leaves hide the decaying ones nicely in the warmer months, so the action of soil building is not in any way an eyesore. Parthenium by contrast has incredible winter texture in its dried seed heads. This plant mines for resources like Yarrow, and redistributes them with its decomposing leaves each year.

A good dry perennial garden would be incomplete without grasses. Both tall bluestem and little bluestem grasses seem to handle drought very well in our clay soils, withstanding even the extreme winter wet of compacted soils. Consider the new cultivar of tall bluestem “Black Hawks” (Andropogon gerardii). This cultivar puts on its fall color – an almost black maroon – by midsummer, and it is just a stunning contrast to many of the white blooming plants mentioned here.

We all know the value of sedums, catmint, lavender and other herbs. But for even more pollinator action include these plants which perform the critical role of host plant: Pycnathemum muticum, Eryngium Yuccufolium, and Monarda punctuate (a particularly useful “spotted” bee balm with an absolutely funky flower). Finally consider the rarer, but more long-lived coneflower: Echinacea Pallida. Unlike its more finicky cousin, Echinacea purpurea, this echinacea stands up to the heat, breaking up soil with its deep tap root along the way. It lives 10 years or more with paler, thin petals that droop gracefully on long, leafless stems, It adds a unique form – especially in the wind.

Finally, lower your maintenance with weed pulling by including ground covers. Pussy toes (Antennaria neglecta) and Wild Petunia (Ruellia humilis) are both built for the dry and inhospitable late summer conditions, and both are valuable host plants in our ecosystem.  

Many of these plants actually need the harsh and neglectful conditions of a hell-strip. The most hellacious parts of your yard can provide a haven for some unique treasures that used to appear all over this region. If you let your soil tell you what to plant, you will eventually be rewarded with less maintenance than a thirsty lawn. If there’s a weed for those rough spaces, then you can count on there being at an intentional plant that fits the bill as well.