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Tips and Tricks from County Master Gardeners Archived Discussion Room

Fairfax County, Virginia

Tips and Tricks from County Master Gardeners

Did you know that Fairfax County has a robust volunteer Master Gardeners program? Now is the time to start planning and planting, and Master Gardeners John Meenan and Sunny Greene are here to help. Join them online Wednesday, April 8 at 11 a.m. to learn more about the program, how to become a volunteer and how to find gardening success with your own plot of land in the county.

Pamela Smith : Good Morning! My name is Pamela Smith. I am the Unit Coordinator for the Green Spring Master Gardeners. I will be transcribing answers to your questions by Master Gardeners John Meenan and Sunny Greene. We welcome any and all questions about gardening. Our mission as Master Gardeners is to help homeowners become better, more responsible gardeners. Don't let the rain get you down! Gardening weather is around the corner.

Robert : I have trouble with my lawn browning out in the hot summer. I assume the roots cannot get deep enough and burn up. What can I do to improve the soil to help get those roots down deeper?

Pamela Smith : Robert,
It is difficult to diagnose the problem with your lawn without first doing a soil test and knowing the type of grass you have in the yard. Free soil test kits are available at every County library. Some publications from the Virginia Tech Extension Office would be helpful. Go to for information on turf grass recommendations and related topics. In addition, Fairfax County Master Gardeners has a home turf program for a $25 fee. Contact or call the Master Gardener Help Desk at 703-324-8556.

Good luck!

Sam : How do you get rid of invasive bamboo that is kiiling my other plants in the yard?

Pamela Smith : What a challenge! Bamboo is very difficult to eradicate. You must be patient with bamboo infestations as this is a multi-year project. To start, remove the stalks (culms) to ground level. Work from the outside in to dig the roots. You will need a sharp spade or cutting tool. When new shoots arise, ( and they will!) repeat the process by stomping or cutting down roots. You can also mow the shoots since bamboo is a grass. Since you have other plants close by, we don't suggest using herbicides.

Good luck and we appreciate your efforts to get rid of this nasty, invasive plant.

Sam : What ground cover would you recommend for a slope that is difficult to mow? The slope is in a location that is part shade and the soil is about 2-inch clay. Deeper than 2 inches and the ground becomes 90% limestone.

Pamela Smith : Hello Sam,
  We don't recommend bamboo! We would suggest grasses (carex) depending upon the sun exposure. Other plants on a slope that work well in poor soil and part shade include day lilies and Christmas fern. Virginia Extension has several publications that would be helpful. Go to and look for "Groundcover for Slopes" publication #426-722 and publication # 426-609.  

Charles : Your suggestion on best tomato varieties for local container growing. Thanks Charles Fairfax City

Pamela Smith : Hello Charles,
   Everyone wants tomatoes! Cherry and patio tomatoes are the easiest to grow in containers but if you want more choices, go to for publication #426-418 and #426-336. Be sure to use the correct size container; 5 gallons for one full size plant and 1 gallon for 1 cherry tomato plant. Also, check your local Farmers Markets in May. The farmers offer seedlings that do well in this area.

Anonymous User : Hi I've applied some lawn food to my grass about a week ago. Yesterday I applied crabgrass control. When is it safe for me to plant some grass? I have a few bare spots. Thanks!

Pamela Smith : Hello Anonymous,
    You have to wait at least three weeks after crab grass application before planting any new grass seed. You may not have much luck with the grass seed since the best time to sow grass is in the fall - mid-August to mid-October. Likewise, fertilizer should be applied in the fall. Remember the first step is always to do a soil test before applying fertilizer or lime to your lawn. The publication "Lawn Care Calendar" can be found at

Anonymous User : I want to plant a raised garden bed, my first. I don't have time for seeds. When can I place plants from a farmers market or garden center? Are temperatures safe enough now?

Pamela Smith : Good Morning,
     Congratulations on starting your first raised bed garden. It is too cold now to plant out seedlings unless you want to grow cold weather vegetables such as lettuce, peas and spinach. Summer harvest vegetable like tomatoes, beans, squash, etc., should not be planted until soil temperatures rise, usually around the 1st of May.

Good luck and enjoy the garden!

Anonymous User : I have a lot of trees with roots protruding above the ground. Should I take any action like calling an arborist? When should I be worried?

Pamela Smith : Hello,
   Action to be taken depends upon the kind of tree you have. Some trees just naturally show their surface roots particularly in the Virginia clay. Be careful not to walk on the roots or go over it with heavy equipment. You can cover them with no more than two inches of mulch for protection. Do not put the mulch close to the trunk of the tree! You will just invite rot. An arborist can tell you if roots are girdling, or circling, the trunk and can help with that problem. Go to for more information.

Mark : when I go to big box garden stores I see all kinds of bulbs and seeds and flowers. Are those "safe" to plant even though most are not native? Do non natives invite more weeds and pests? The only native bulbs I've seen at these stores is liatris.

Pamela Smith : Mark,
  Choosing native plants is always a good idea. However, most bulbs are not native but are still fine to plant in your yard without concern for increased weeds or pests. The squirrels may try to rearrange them for you but there is no need to worry about invasive tendencies.

@ejstrick : I have a puppy that is tearing a path in our shaded backyard with his wind sprints. Suggestions for grass/grass substitute that I can plant to protect from the mud? Thanks

Pamela Smith : Hi,
  Dogs will be dogs! There isn't much you can do about a sprinting canine on grass. We would suggest creating a path and putting mulch down.

ashley : Is rain barrel water safe for vegetable gardens? I've read conflicting advice. I have a typical slate roof. Thank you.

Pamela Smith : Ashley,
  Rain barrels are a great way to water your garden plants, including vegetable. The slate roof will slough off tiny particles of stone dust. This should settle into the bottom of the rain barrel and should not affect your plants. You may want to make sure that you clean it out regularly to get rid of the collected dust particles so as not to clog the hose.

mdcoon : What kinds of plants/trees/shrubs are good for swampy parts of your yard? And won't invade the sewer or water lines?

Pamela Smith : Hello,
  Not knowing the size of your yard, it is hard to make suggestions for trees. All tree roots will entangle themselves around sewer pipes, willows being the worst.  Go to  publication #430-026. We suggest sticking with shrubs in this area. For more in-depth information on shrub choices, call the MG help desk at 703-324-8556.

Pamela Smith : Thank you for joining us today. If you are interested in becoming a Master Gardener, please send an email to me at
Visit us at Green Spring Gardens to get ideas for your home garden. Our help desk opens at Green Spring on April 11 from 9:30 - 3:00 pm every Saturday, except holiday weekends, through September for answers to your gardening questions.
Happy Gardening!
John, Sunny and Pam