Does Planting Flowers Close to the House Make the Basement Flood?

Xeriscapic Flowers

• In humid areas where there is plenty of soil moisture, gardeners should only plant drought-tolerant flowers near the perimeter of houses. Drought-tolerant plants are "xeriscapic," which means they rely on natural rainfall after they establish strong roots.

  According to the Clemson University website, even if gardeners plant water-guzzling species 10 feet away from a foundation wall, the amount of watering necessary can cause basement moisture problems. Examples of xeriscapic plants include the perennial daylily (Hemerocallis) and annuals such as cosmos and moss rose (Portulaca grandiflora). But xeriscapic plants need daily watering until their roots are well established. To grow cosmos from germination through seedling stage takes about five weeks. It can sometimes take a whole growing season of daily watering to establish new perennial plantings.

Expansive Soil Landscaping

• Clemson recommends that you don't plant under roof eaves to keep soil that is close to the foundation as dry as possible; damp walls can lead to mildew and pests such as termites and roaches.

  Gardeners who regularly water a foundation bed on one side of a house contribute to uneven moisture conditions if the soil is expansive. Expansive soils swell during rains or heavy garden watering and shrink when conditions are dry. Uneven expansion and contraction heave basement floors and crack foundation walls.

Expansive Soil Solutions

• The Colorado State University Extension website states that the wisest choice is not to plant along foundations that rest on expansive soils. However, the site makes an exception for groundcover plants, which keep expansive soil evenly moist.

  Another solution to the problem of soil expansion and contraction is to place an impermeable fabric barrier, such as a rubber apron, underground near the house. Contractors should place the barrier fabric directly on the foundation wall at soil level and go down 3 inches, according to the Irrigation Tutorials website. Rocks or bark mulch cover this no-water zone. Normal planting can be maintained outside the barrier.

Rain Gardens

• The Colorado State University website recommends that homeowners connect the roof gutter system to a downspout that is long enough to direct rainwater at least 5 feet away from foundations. To redirect rainwater even further away, connect the downspout to an underground French drain that leads to a rain garden at least 10 feet away and on a downward slope from the house.

  The University of Rhode Island suggests that homeowners plant rain gardens in full sun and in locations where water doesn't puddle, since puddling indicates poor drainage.