Choosing Your Plants: Growing Conditions
Choosing native plants that are compatible with your soil can be very important to their success in your garden. Every plant has a range of soil types and conditions in which it can easily flourish. Some species thrive in a very wide range of conditions, but others have very specific soil needs. For instance, Yellow Coneflower, Black Eyed Susan and Bergamot will grow in a wide range of soils and moisture conditions. But species such as Lupine and Rough Blazingstar only thrive in dry, well-drained sandy soils.
Soils can be divided into three basic types, based upon their mineral (non-organic) content: sands, loams, and clays. There is variation within these groups, but these basic types offer a good guide for describing where a plant will or will not grow.
Clay soils are commonly known as “heavy” soils." They consist of very small, tightly-packed soil particles, and tend to be dense and hard to work. Clay soils absorb water more slowly, and retain it for a longer period. When wet, the soil becomes slick and will form sticky clumps. When it dries out, clay soil becomes hard and solid.
Loam soils are intermediate between sands and clays. Loam soils are quite fertile, but instead of high clay content they have roughly equal proportions of sand, silt and clay. This is ideal because it holds plenty of moisture but also drains well enough for sufficient air to reach the roots. Most plants will thrive in loam soils.
Sandy Soils, referred to as “light soils," contain large-sized soil particles that are loose and easy to work. They tend to be very well aerated, very fast-draining, and do not contain much in the way of soil nutrients.
Extremely well-drained, dry soils rarely have standing water, and rainfall drains rapidly through them. A surprising variety of native plants will thrive in dry soils without any soil amendment or irrigation.
Medium soils (mesic soils) sometimes experience standing water, but only for short periods, such as after a heavy rain. These are typically loamy and clay-based soils with good drainage.
Moist soils typically occur in low-lying areas, and have moist subsoil throughout the growing season. They may experience periods of standing water during dormant seasons, as well as after significant rainfall events during the summer.
Wet soils stay damp nearly year round, and moisture is generally available within one foot of the soil surface, even in mid-summer. Wet soils are often flooded in spring. Only the most moisture tolerant plants will thrive in wet soils.
A site with 'full sun' will receive full, direct sunlight for more than 6 hours a day. In nature, full sun is analogous to meadows, prairies and other open country.
Partial Sun or Partial Shade
Partial sun and partial shade are fairly inter-changeable. Areas that receive between 4 and 6 hours of sunlight per day are 'partial shade'. Oak Savanna and woodland edges are the natural home of native plants that prefer partial sun/shade.
In terms of native plants, full shade = woodland plant. Full shade plants prefer very little direct sun. They like less than 4 hours of direct sun a day and prefer morning and evening sun to mid-day sun. ‘Full shade’ plants also do well in dappled shade conditions.