Extension agent to answer lawn & garden questions

March 24, 2009

This chat has already taken place. Read the transcript below.

Jennifer Smith

Jennifer Smith, extension agent for horticulture with the Douglas County Extension Office, will participate in an online chat at 1:30 p.m. Tuesday. She can answer questions about your lawn, garden, trees or anything else horticulturally related. Post your questions any time.


Hi, everybody. Welcome to today's chat. Jennifer Smith, horticulture agent with the Douglas County Extension Office, is here to answer your lawn and garden questions. Thanks for be here, Jennifer.

Jennifer Smith:

Hi everyone. I'm glad to be here and hope I can answer your questions!


We have a bunch of questions, but keep them coming in. We'll go ahead and get started.


When can I start planting vegetables and flowers outside? What is the latest freeze date here?

Jennifer Smith:

Some things can be planted outside now, like perennial flowers, trees, shrubs, and cool season veggies. Lettuce, radishes, potatoes, onions, and broccoli are some examples of veggies.
The average last frost occurs around April 13-15, but the true "frost-free" date for this area is May 2. For annual flowers like petunias and warm-season veggies like tomatoes, peppers, and squash, wait until May or plan on covering the plants on cold nights.


I have three 4' x 5' areas in my yard where the grass has been worn away due to heavy foot traffic. I have tried seeding but have been unsuccessful. Should I resod these area? If so how should I prepare the ground (compacted soil and alot of tree roots) and when should I do this? Can I apply crabgrass pre-emergent before I sod?

Jennifer Smith:

You could seed or sod the area, but if you decide to seed, do it prior to April 15 to allow the grass to establish before summer. Since the area is compacted, the grass seed is probably having a hard time breaking through the soil surface. With seed or sod, you should try to loosen the soil by core aerating or tilling the bare area. Try to avoid damaging the tree roots if you till (I know this is easier said than done).

The crabgrass pre-emergent will also keep grass seed from sprouting and could interfere with sod establishment. Different products have different time requirements, so make sure to check the product label for specific recommendations.


Our neighbors have a trumpet vine that grows on and over our shared fence. It is ruining our fence and we now have vine coming up randomly all over the yard. Is there any way to keep this from spreading?

Jennifer Smith:

Unfortunately, trumpet vine is very hard to control. It is considered a noxious weed in some states although it has not yet reached that designation here. Just try to get ahead of it if you can, by removing the plants when they are small. I would also try to make good friends with the neighbor!


Would you recommend replacing a dying locust tree with a new one? Or are there other shade trees that you would recommend?

Jennifer Smith:

I wouldn't recommend replacing a tree with the same species in the same spot if the tree has died of a disease or from a site-related problem. You might check on the mature size of these trees before making a decision, but some of my favorite trees for this area are London planetree, Lacebark elm, Sawtooth oak, Shumard oak, and Norwegian Sunset maple. The Kansas Forest Service also has a list of trees recommended for NE Kansas on their website.


Can banana plants be planted outside in this area? If so, what needs to be done to help them survive the winter? What kind of care do they need througout the year?

Jennifer Smith:

Banana plants can grow outdoors here in the summer, and if you are lucky, you might even get some fruit! To survive the winter, they will need to be stored in a cool, dry location where they won't freeze, like a basement or cellar. You can also cut them back in the fall to ease storage. Through the summer, water, add a little fertilizer when you first bring them outdoors, and keep an eye out for insects and diseases.


We have a large open backyard that faces north and have tried to plant new trees that have all succumbed to (I suspect) to deer. We have tried planting flowering pears that have all died. It looked to me the bark was getting stripped. A new birch tree lost two of its three main sections last year. Even a maple tree is really just limping along. Water is not a problem -- we have a sprinkler system. What trees could we plant that would be deer resistant? These trees were all professional planted by Sunrise Garden Center. Our soil may not be the greatest, either. Anyway, thanks very much.

Jennifer Smith:

Deer are hard to compete with. A tree's vascular system lies just inside the bark, and if it is damaged, it often kills or severely damages the tree. Even trees that are supposed to be deer resistant are sometimes damaged. You could try using metal stakes in a circle around the tree to keep the deer from getting to it, or there are plastic tubes available that fit around the main trunk of the tree that work well. The bad thing about the plastic tubes is that they are only available online and don't work for multi-stemmed trees like the birch. Staking should work for this situation, though.


How exactly should I prune my butterfly bush to ready it for spring and summer?

Jennifer Smith:

The simple answer is to prune branches back to a live bud. You should start seeing green buds anytime now, if not already. If you want to reduce the size, you can cut the bush back very short, or you can just prune out the dead tips.


Can you recommend some plants that thrive here in the shade?

Jennifer Smith:

For shrubs, there are a few different species of viburnum (read labels and check at your favorite garden center), and hydrangeas (some species grow better in this area than others). For flowers, hostas, coral bells, ferns, columbine, and wild ginger all grow well. One of my favorite shade plants is the Toad lily, that blooms in August-September and has a very unique, lily-like flower.


I have loads of evergreen trees on my property that I believe are Austrian Pines. Some have turned brown & died, and I was told that they can be sprayed for some type of disease, but it has to be done only at a certain time of the year. Any truth to this, and when is the time?

Jennifer Smith:

If they are Austrian pines, they probably have Diplodia tip blight. This disease does have to be treated at a specific time, in mid-late April and May, and will require 2-3 fungicide applications depending on which product is used. This treatment has to be done every year and does not guarantee protection against the disease. The better treatment is to replace the trees. The dead ones especially should be removed as soon as possible because they may be infected with another disease, pine wilt, that could take out the rest of what you have.


In your opinion, what organic soil amendments should be added together to make both a container garden and a seed tray. Seed plantings would be transplanted in an outdoor garden. Also, any tips or tricks for how to keep your organic plants healthy despite the occasional gust of herbicide from the neighbors. Thank you!

Jennifer Smith:

I prefer to use soil-less potting mixes for both seed trays and container gardening. They drain better and are lighter weight, and organic options are widely available. If you do use soil, mix with a lightweight "finished" compost - it should almost look like soil and be dark and crumbly. As far as the neighbors go, it depends a lot on whether you are upwind/downwind, or if there is a structure inbetween. I'd try to keep a house or shed or some trees between them and the vegetable garden if you can!


Are there fertilizer and weed treatments that are better/safer to use when you have children and pets that play in the yard?

Jennifer Smith:

If you do a good job of growing grass, you can avoid using weed treatments. Mow as high as your mower will allow (2 1/2- 3 1/2 inches), let the clippings return to the lawn instead of bagging, and fertilize in September. Water only deeply and infrequently when needed in the summer. There are several organic fertilizer options, like Milorganite and Bradfield organics. Topdressing the lawn with compost in the spring and/or fall will also provide important nutrients and improve the health of your grass.


That's all the time we have for today's chat. Thanks, Jennifer, for coming in. Also, you can check out her Garden Calendar column Thursdays in the Journal-World and here at LJWorld.com.

Jennifer Smith:

I enjoyed chatting with you today. If you have more questions, please e-mail me at smithjen@ksu.edu or call me at 843-7058. Happy Gardening!


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