Most of us have areas of our yards that are more of a challenge than others. When I asked people to send in their landscape problems, several of them spoke of areas where nothing would grow. Such is the case for the Kirkharts of Andover. In this installment of Landscape Solutions, landscape architect Kurt Huiras of GLMV Architecture addresses their case of the dreaded clay soil on the north side of the house.
No matter what your trouble spot, Kurt’s guidelines likely will help you with plant choice, soil and irrigation.
Problem: Nothing will grow on north side
On the north side of our house, we can’t get anything to grow. My husband says it is clay dirt. We are in our 70s and can’t do too much and don’t have a lot of money. Thank you.
Solution: adaptable plants
The north side of a building can indeed be a difficult place to grow plants. Soil type, shade, bed size and irrigation can be factors that influence your choice of plant material.
• Clay soil poses several problems for plants. It compacts easily, holds water, traps nutrients such as iron, and is typically alkaline. The best way to amend clay soil is to add organic material such as compost. Till the top 8 to 10 inches of soil, then cover the area with about 2 inches of compost and work it into the soil until it is thoroughly mixed.
This is a temporary solution, because soil tends to revert back to its original condition. So, soil amendments can be effective if you are planting annuals, where you can till the soil annually, but they are less effective for permanent plantings such as trees, shrubs and perennials. It’s best to choose plants that are adapted to clay soil.
But that may not completely solve the problem. Your soil also may be depleted of nutrients. A soil test will help you determine the best fertilizers or amendments for your planting beds. You can contact your local Kansas State Extension Service to get a fairly inexpensive soil test that will give you recommendations.
• A planting bed on the north side requires you to find plant material that will handle full shade. Your house also can act as a screen to limit the effect of the weather in both positive and negative ways. For instance, the building eaves can keep rain from reaching the plants, so irrigation may be necessary. But the building also can be a positive factor by protecting plants from hot summer winds.
• Bed size is another often overlooked consideration when choosing plant material. A narrow bed such as yours will require compact plant material. You need to choose plants based on their mature spread in order to limit the maintenance and to take full advantage of their aesthetic qualities.
The plants should be placed so that the mature spread of the plant is one foot away from the building wall as well as six inches away from the planting bed edge. Plants of the same species should be placed in groupings so they touch when they reach their mature spread, while plants of different species should be separated by about six inches at their mature spread.
Here are examples of plants that would be appropriate for your bed size:
• Shrubs such as Peewee hydrangea or Green Gem boxwood.
• Perennials such as hosta, lamium, liriope, lily of the valley, coral bells or ferns.
• If you want to add some annual color, I would go with impatiens or begonias.
I would tend to go with a simpler planting for a bed of this size, with a taller plant such as the boxwood or hydrangea in back and one of the shorter perennials such as the liriope as a border. You also could substitute the impatiens or begonias as the border for more color in the summer.
The tendency of clay soil to hold moisture makes proper watering very important for the survivability of the plant material. An irrigation system can be a great way to ensure that plants get the water they need, but it needs to be properly designed, with a head-to-head layout, so that one head throws water all the way to the next adjacent head. Drip irrigation is a cost-effective alternative to spray heads in beds.
An irrigation system also needs to be zoned based on plant type and exposure. Lawn areas and sunny areas will require more water in the summer to remain green, so a shaded bed should be zoned differently or it will probably be overwatered. On the other hand, you may be underwatering if you only have a single head rather than head-to-head coverage.
By picking the proper plant material based on site and soil conditions while ensuring proper irrigation, you can make the narrow bed a positive feature that will accentuate the north side of your house.