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We have a ravine with native plants (trillium, trout lily, etc.), and we need to control erosion. What plants would you recommend? What about pachysandra? Will it overtake and kill the natives?

It sounds as though you would like your ravine to be naturalized with native plants based on your choice of wildflowers. There are many native plants that you can use for erosion control.

The dwarf crested iris (Iris cristata) is a tiny lavender iris that will spread in high open shade and blends well with wildflowers. Cleft phlox (Phlox bifida) has star-like, lavender-blue flowers in the summer and is good in sandy, well-drained soil as an accent groundcover. Fragrant sumac (Rhus aromatica) is a shrub-type groundcover that suckers heavily and prefers sun, but will tolerate shade. It has small, yellow flowers in the spring, followed by clusters of hairy red berries that persist throughout the winter. It does get taller than traditional groundcovers; 2 to 6 feet. ‘Gro-low’ is a new cultivar of sumac that only grows to 2 feet.

There are some prairie grasses that will bind the soil tightly in almost any type of planting environment. These include prairie cord grass (Spartina pectinata), switch grass (Panicum virgatum), sweet grass (Hierochloe odorata) and big bluestem (Andropogon gerardii). Small sedges like Carex pensylvanica make excellent groundcovers under trees, especially oaks.

When deciding to mix and match, it is important to study the growth habits of the plants you are using, as some can be so aggressive that they will overrun nearly all of the other plantings. The rhizomatous natives such as Canada anemone (Anemone canadensis) and prairie cord grass are very effective erosion controllers but need room to run.

Japanese pachysandra (Pachysandra terminalis) is the typically used landscape groundcover, but there is a native pachysandra, Allegheny spurge (Pachysandra procumbens) that is really more interesting. It is a little taller, 6 to 12 inches, with scalloped leaves that are gray-green and become mottled with age. It has fragrant pink-white flowers that look like spiky bottlebrushes. It grows from a thin, white creeping rhizome with prominent eyes for the next year’s growth. It is slower growing than the Japanese pachysandra.

When do I trim back the mums in my garden? I would like to keep them about one foot tall. How often and how much of the plant can I safely remove at one time to keep them at the desired height? After blooming in the fall, how much of the plant do I cut back? Also, when and how should I divide the plants? How many divisions can I make of one plant?

Mums planted the year before should have new tip growth pinched back every 2 to 3 weeks beginning when they are about 6 inches tall and until about the first of August. This makes them full and bushy, and loaded with blooms. It prevents the tall leggy mum that opens up in the center and flops down. Repeated trimming holds down their height.

This year, however, our hot weather has accelerated many of our plants. So if you sheared or pinched your new growth in early August, you probably sacrificed any fall blooms before the first hard frost. If you don’t have the time to trim back tip growth every 2 weeks, a rule of thumb is to trim the plant by half around Memorial Day and trim again by only a third around the Fourth of July.

In late fall, the first hard frost generally kills the vegetative growth. Once the plant is dormant, cut off the stems about 4 to 6 inches above the ground, clean up old leaves and debris, and mulch the area. In spring, when new growth appears, you can make more plants by dividing the new offsets from the original crown. You are only limited in the number of new plants by how many offsets the crown has produced. Remove them carefully with as much of their root system as possible. Transplant to your area of choice or place in pots for later planting.

I have a problem area under my maple tree (tree roots and shade). I want to plant flowering perennials with a maximum height of 6 inches that would provide blooms throughout the summer. Are there such plants?

The area under maple trees is deep shade with dry, root-filled soil and it presents a challenge, but is not impossible to garden. The trees absorb the moisture first, leaving plants underneath thirsty. The soil often lacks nutrients as the trees absorb them first as well. And, of course, there is the lack of light. Thinning the tree branches overhead allows more light to reach the ground.

Before planting anything, add copious amounts of good compost, aged manure, leaf mold and other organic matter to improve the soil structure, nutrients and water retention. Improving the soil will help the following plants do well under your maples.

You may want to consider a groundcover. This works whether you want a formal or a naturalized effect. Groundcovers tidy up the garden, hide the mulch and define the edges. Some groundcover choices are deadnettle (Lamium), pachysandra, myrtle (Vinca), and lily-of-the-valley. Lilyturf (Liriope) is a small, clumping grass-like plant that has small flowers on a central stem. There are some lovely perennials that will be happy in your location. Barrenworts (Epimedium) are known for their neat habits and undemanding requirements.

There are some nice choices for leaf and flower color as well. Sweet woodruff (Galium odoratum) is a deciduous groundcover that will quickly develop huge mats of soft green stems that smell like vanilla. Early spring bulbs, corms, and tubers like crocus, Siberian squill (Scilla), and Cyclamen coum, which will bloom and then go dormant, seem to prefer dry summer conditions. All kinds of hardy geraniums will grow well and flower throughout the summer as long as you deadhead them in mid to late summer. Pigsqueak (Bergenia cordifolia) will take fairly deep shade, producing flowers in mid-spring.

Coral bells (Heuchera) are reliable plants in the shade and new cultivars are appearing every year that have many interesting leaf colors from burgundy to silver to bronze. Their small bellflowers on wiry stems show off all summer. Heucherella is a cross between Heuchera and foam flower (Tiarella) and is also a good selection. ‘Quicksilver’ is especially nice with silvery, metallic leaves that reverse to a rich, red purple. Hostas are also appropriate and make a pleasing picture when planted with coral bells and Heucherellas. Add Japanese painted fern and you have a lovely variety of color, size and texture.

What exactly are the suckers on tomato plants? I was told that if you pinch them off, your plant will concentrate on growing the fruit, instead of producing the suckers. When should I pinch them off? How do I determine which ones they are?

Pruning directs a tomato plant’s energy from producing foliage to the production of fruit. Pruning involves removing the lateral branches—also known as suckers. Suckers arise at the junction of the leaf and the stem.

Some of the advantages of pruning are larger fruit, earlier-maturing fruit, the ability to have closer plant spacing, easier pest control, and easier harvest. The disadvantages of pruning can include fewer fruits per plant and increased labor.

The primary factor in determining how severely to prune a plant is the plant type—indeterminate or determinate. An indeterminate plant keeps growing and producing fruit until it’s killed by frost or disease. When the branches of a determinate plant reach a certain length or age, they stop growing and producing fruit. 

The indeterminate varieties are generally pruned down to one or two main stems. In the single-stem system, all of the lateral branches, or suckers, are removed. In the double-stem system, all but one of the suckers are removed. The sucker immediately below the first fruit cluster is allowed to grow and produce a second stem, which will also produce fruit. All suckers on the second stem are removed.

The suckers on determinate plants are normally removed as they would be in the double-stem system with indeterminate types. The sucker immediately below the first fruit cluster is left intact. Depending on the natural vigor of the variety, two or three suckers below this fruit cluster may be left intact.

If you are going to prune, wait until the suckers are large enough to handle easily (1 to 2 inches long). Simply pinch or snap off the suckers. Keep an eye on the lower branches of a tomato plant for further pruning. The lowest branches are prone to be the first infected by fungi or disease, as water splashed from the ground may carry spores to the lowest branches. When the branches and/or the leaves show signs of spotting or yellowing, the entire branch should be pruned and the material disposed of. Do not compost this material as the compost pile may not get hot enough to sterilize it.

I would like to grow some vegetables, but I work long hours during the day, so I don’t have that much time to devote to the garden. What vegetables would you recommend that I try?

Low-maintenance vegetables to grow would be peas, beans, peppers, cucumbers, and tomatoes. Once these plants are established, there is little time involved other than watering, weeding and fertilizing. Stay away from trying to start your own plants from seed. To save time, buy well-established vegetables from your local garden center. This will not only save time, but will also give you a couple weeks jump start on your garden.

Soil conditions are very important. Adding sphagnum peat will help with drainage and help retain moisture as well as enrich the soil.

More time is usually needed at the beginning of any garden – whether it is an annual, perennial or vegetable garden. Once plants are rooted, your garden will take far less maintenance other than a few hours a week.

I have moss growing in my lawn. Why is that? Is it a problem? Should I get rid of it? If so, how?

Moss, like any other weed, is very opportunistic – where the ground is bare and conditions are somewhat favorable, it will grow. Moss can be very beautiful in the right setting, but in the lawn it is a weed.

Moss grows in most any soil, in sun or shade, under acid or alkaline soil conditions. It tends to do best where the soil is slightly to heavily compacted and where it is frequently moist.

Moss hugs the ground tightly but has no root system. Large areas can simply be raked off. Burn-off type killers such as Security Moss and Mildew Killer, and Scott’s Moss Control for Lawns quickly turn the moss brown. It will then disintegrate into the soil or can be raked away.

To prevent the moss from growing back, loosen the soil, aerate if practical, and reseed the large spots. Remember, your best deterrent against any weed (including moss) is a good, thick turf.

On the north side of my house, there is mature English ivy (6 or 7 years old) growing well in a 6 by 25 foot area. How can I get rid of the ivy and prep the area for planting? (I need more space for perennials!) I would rather not use herbicides, but pulling up all that ivy would be really tough. Any suggestions?

Unfortunately, English ivy is a very tough plant to remove without the use of an herbicide. As you stated in your question, pulling up all the English ivy is going to be difficult at best. Not only is it tough to physically remove the vine, it is going to be even tougher to remove all of the roots from under the ground. This plant can sprout back up from roots that are left in the ground, so it is very important to remove everything, which is not an easy task! English ivy is even hard to get rid of with your “average” herbicide. It is recommended to use a more powerful herbicide such as Bonide Poison Oak & Ivy Killer in accordance with the directions on the bottle.
With a plant as tough to remove as English ivy, the only real alternative is to use an herbicide. I hope this does not deter you from making more space for your perennials!