A Hellstrip/Parking StripGarden is a low water garden created in the often hot and neglected area between the sidewalk and curb or along a driveway. It is often a challenging area for a garden with poor soil and little irrigation available. The best plant choices for these spaces are low growing, tough, drought tolerant dryland plants.
Soil composition and fertility - Most dryland plants do best in low fertility soil, but they do require enough soil to put down roots. 6-12" soil depth is ideal. If you are creating a garden with less than 6" of soil, you may do better to stick with succulents since they are generally shallow rooted and store water in their leaves rather than needing deep root runs. We are able to grow a wider range of plants in our hellstrip (see below) because the plants will tap into the native soil in a season or two, obtaining additional moisture and nutrients. You will generally not need to add compost or supplemental fertilizer to a dryland garden.
Drainage - If you have heavy soil or there is standing water in the area during the rainy season, you will need to improve drainage. Planting on mounded soil is a good method to improve drainage but it is not always practical in a hellstrip. We have had good luck working a few inches of 1/4-10 crushed rock into the soil. It doesn't seem like much, but it really seems to improve the health and vigor of the plants.
Water Needs- If you are lucky enought to live in an area that receives regular summer rainfall, your garden will probably not need supplemental water. However if you live in a summer dry climate like ours, your garden will do best if it is watered a few times during the dry season. It may be frustrating to hear that some summer water will greatly benefit your plants, particularly during the first season while they are becoming established. After all, the whole point is to create a low maintenance garden. However, if you bite the bullet and provide occaisional water, your plants will look better and you will be happier with your efforts. If watering is simply not practical or desirable, do not despair. While they may not grow as lush as in irrigated soil, most drought tolerant plants will survive the first seasons and begin to thrive without water as the years go by. You can also include summer dormant plants in your garden. Spring bulbs generally do fine without summer water. Succulents such as Hens and chicks and our NW native Sedum spathulifolium, while evergreen, don't need water in summer because their main growth periods are in the fall and winter.
Create a Hellstrip/Parking Strip Garden using Pocket Planting
A hellstrip garden is often created in the neglected space between the sidewalk and curb but it can also be created along the edge of a driveway as we did at Wild Ginger Farm. We selected our toughest, most drought tolerant plants to create a colorful and attractive garden to welcome visitors to our nursery.
Hellstrip Gardens are often created in the least hospitable areas, hence the name hellstrip. We certainly had that problem when we moved to our new nursery site. The area along our driveway had been used as a gravel roadbed pile by the previous owners. We wanted to create a low maintenance garden in this hot, dry and unsightly area but found that we were unable to penetrate the rocky, compacted soil with our tiller or even with a handpick.
One of our goals at the nursery is to test the limits of our plants, so the first season we simply dug some leftover black basalt rocks into the edge of the bed and planted the plants directly into the rocky, soiless surface. As you can see below, the plants after a full season's growth survived but did not thrive.
Before pocket planting
The next year we replanted existing plants and added additional plants using a pocket planting method. Pocket planting is used when you are unable to rework the soil in an entire area. Instead, a hole is dug and additional soil is worked in along with the plant. I would guess we never added more than a gallon's volume of a well-draining soil blend to each planting hole, but what a difference that little bit of soil made! The photos below, taken a few months after replanting, show how the plants have been able to thrive when planted in a small amount of soil over our original impenetrable rocky area. Over time, their penetrating root systems will work their way down to the soil substrate below. Once this occurs they will become even more drought tolerant and will also be able to obtain any needed nutrients from the soil.
After pocket planting
Plants include Euphorbia characias at rear against shed, mounding Sedum ellacombianum in the middle of the bed, and a combination of Creeping Thyme, Snow in Summer (Cerastium tomentosum), pink and white flowered perennial baby's breath (Gypsophila repens), Alpine Scullcap (Scutellaria alpina),and Hens and Chicks (Sempervivum spp.) along the edge.