Issue: February 11, 2000

No grass growing under trees

I have a beautiful front yard that has three very BIG trees. The problem is that there is no grass under these trees. What type of seed should I plant and what other advice can you give me? Please help!!!

It is very difficult to grow grass under trees. In a forest there are few grasses, and those that are there do not form a nice carpet like a lawn under the trees.

Trees are effective at intercepting the light needed by grass to grow. Even though there is light under the tree, the wavelengths of light most needed by the grass have been removed. The shade of buildings does not inhibit grass growth as well as tree shade because buildings do not extract specific wavelengths from the light.

Trees also intercept the rainfall and divert much of it to the dripline of the tree where it is more useful to the tree and where there may be more light to allow grass growth. Nearer the trunk of the tree, inside the dripline, water deficits also limit grass growth.

For these reasons, if the tree creates a dense shade, it is best not to try to grow grass under the tree. In the densest part of the shade, mulch or flagstone paving, along with lawn chairs, are the best solution. Be careful not to damage tree roots when placing the flagstones. If there is sufficient light penetrating the tree's foliage, it may be possible to grow some groundcover plants which are adapted to lower light levels.

Amaryllis flowers too tall

Why do our amaryllis stems always get extremely tall before the blossoms open? If we don't provide extra support, they will topple over. We generally keep the temperature of the house below 60 degrees.

It is natural for amaryllis flower scapes to become rather tall, but they should be capable of supporting the flowers without falling over. However, in a pot with a small bottom it becomes unstable and is prone to toppling over. Don't transplant it now, but you can place it into a larger diameter pot or decorative container. Place some gravel or rocks in the bottom of the pot to increase the weight or this container and allow drainage. Be careful that no water collects around the base of the pot containing the bulb as you water the plant.

Under indoor conditions, light may be limiting. Low light levels will increase the height of the flower scapes. You are doing the right thing to keep the temperatures cool in the room where the plant is growing as this helps reduce the excess height of the flower scape. While it is flowering and the leaves are absent or dormant, fertilizing is not important. Too much nitrogen fertilizer may also cause excessive flower scape growth. If you fertilize before and during flowering, use a flowering houseplant fertilizer that is low in nitrogen and higher in phosphorus. Nevertheless, the amaryllis is genetically programmed to produce tall flower scapes.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!