Question: Can clematis vines be used as a ground cover? If so, how far apart should they be planted and how do you recommend planting them? What fertilizer to use? I'm trying to inexpensively cover a very large steep bank between our lawn and the road. It is mostly in sun, but parts are shaded by trees. I need something that takes care of itself and that will tolerate road salt. It needs to be fast growing, vigorous and gets planted far apart, so I don't have so many holes to dig. Can I plant bulbs for spring color under clematis?

Answer: The only clematis that is sufficiently vigorous to meet your requirements is the Sweet Autumn Clematis (usually sold as Clematis paniculata and sometimes commonly called Virgin's Bower) with small white fragrant blooms over a long period from August until October. Clematis paniculata is usually grown as a vine, but can be grown as a ground hugging cover. It grows in full sun as well as dense shade and will tolerate road salt. Is so vigorous that it will crowd out almost all weeds. Because of the density of the ground cover, I doubt that even the most durable of spring bulbs will survive for more than a few years.

First I recommend weed killing the bank with Remuda, next applying a granular weed preventer such as Amaze, and then mulching with two to three inches of tan bark mulch. This process will help prevent weeds from taking over until the clematis fills in solid to form a weed-inhibiting ground cover. Depending upon how far apart you plant the clematis vines it will take two to three years for them to grow together solidly. I recommend spacing the clematis between eight to ten feet apart. Because of the wide spacing, and fewer plants purchased, your ground cover will be relatively inexpensive.

Plant them in a half-and-half mix of your natural top soil and Chesapeake Blue crab compost, along with a handful of granular Bio-Tone Starter Plus for each clematis. Fertilize every year in late fall and early spring with Kelp Meal and Plant-tone. If the clematis builds up too far on itself, every few years you may have to cut it down to about a foot high with a power hedge cutter. In your situation, I would use one that operates from a long pole such as is made by Stihl. Clematis paniculata will make a beautiful, weed-inhibiting ground cover that will require almost no maintenance. It is incredibly drought tolerant and should never require supplemental watering once established.

The lawn mower will keep it from creeping up into the lawn and the road traffic will keep it from creeping out into the road.

Question: Plants that look like Scallions are growing in clumps in our compost pile. I tasted one and it tasted like a scallion and I'm pretty sure that I have true edible scallions. Do you have any idea where they came from?

Answer: If you cut the roots off of a scallion (spring onion) and leave a little bit of the stem attached, it will grow into a new scallion. I'll bet yours originated with scallions that were composted after the tops were used in the kitchen or that had spoiled in the refrigerator. When they buy scallions in the supermarket in spring, some people use the leaves and most of the stems but purposely leave a little bit of the stem on the root and plant them, thus making a crop for later harvest.

Question: I've heard folks say that fall is for planting. Exactly why is that?

Answer: Most plants are better planted in the fall because fall is the season for root growth. In the fall air temperatures drop more quickly than soil temperatures. Although the leaves and stems are heading into dormancy, the roots will continue to grow until the soil gets really cold. In the spring the air warms more quickly than the soil. The tops start to grow before the roots do. Thus, because of their superior root systems, fall-planted plants require less TLC in the spring and summer than those planted in the spring. Also there is almost no concern about transportation and handling damage to the foliage and flower buds because, in most cases, they haven't formed yet.

Question: I have nut sedge. I was listening to your show last week, but I missed what your guest said – something about not watering.

Answer: Tony Richardson, "The Lawn Doctor" suggested not watering the lawn for three days after apply Sedge Hammer. Incidentally he also mentioned that enhanced Round-Up-type sprays will not result in total control of nut sedge, but regular glyphosate will.