Each year my impatiens grow very tall (over 2 feet) and are healthy, but they are not covered with flowers like those I see at other homes and even commercial plantings. How can I get my impatiens to grow lower and give me that “carpet of color” effect?

Impatiens are a good selection for shady spots for a number of reasons—the plants thrive in both beds and containers, plus they come in a wide range of flower colors including red, orange, salmon, rose, pink, white, violet, and lavender blue. New Guinea impatiens also offer exciting variations in leaf color.

With proper care, impatiens will fill your flower beds with color until frost. To ensure impatiens flourish, you need to do several things. First, plant impatiens in the right soil. The plants prefer well-drained soils with a pH of 6.0 to 6.5. After preparing the soil, you are ready to plant.

Choose healthy transplants, free of disease and pests, from a local nursery or garden center. The common impatiens actually prefer shade. The New Guinea impatiens with variegated foliage will tolerate morning sun. Take this into consideration when you select plants. Space tall-growing varieties 18 inches apart and compact varieties 8 to 10 inches apart. The closer they are planted, the taller and leggier the plants grow.

Once plants are in their containers or beds, provide them with ample water. Impatiens need plenty of water during the hottest parts of the summer. Check plants regularly. You may need to water daily during hot weather. Plants under stress from insufficient water will not bloom as heavily as healthy plants. Use soaker or drip hoses in flower beds. These hoses put the water where it’s needed (the roots) and are more economical than overhead sprinkling.

Impatiens respond well to fertilizing. Applying a water soluble fertilizer once a week encourages foliage and flower development.

When the summer really begins to bake the garden, impatiens may look spindly and leggy with only tufts of foliage at the top of long stems. There’s an easy solution to that problem: Pinch or cut back stems to within three inches of the plant’s base. Impatiens have suppressed leaf buds along their stems. When you remove the upper growth, the plant responds by opening the suppressed buds. This pruning will encourage a new flush of growth and blooming for you to enjoy the rest of the season.

I read that you should never plant the sweetgum tree (Liquidambar styraciflua) between the sidewalk and the street because of the spreading roots, but is this true for all varieties, such as ‘Moraine,’ ‘Burgundy,’ and ‘Rotundiloba?’ Which variety is more cold hardy in Michigan? I read that ‘Rotundiloba’ has no spiky gumball fruit, but is it hardy to zone 5? Finally, which variety can be counted on for reliable fall color?

Sweetgum (Liquidambar styraciflua) grows in a narrow pyramid to a height of 75 feet and may spread to 50 feet. The beautifully glossy, star-shaped leaves turn bright red, purple, yellow or orange in the fall. On some trees, particularly in the northern part of its range, branches are covered with characteristic corky projections. The trunk is normally straight and does not divide into double or multiple leaders. Side branches are small in diameter on young trees, creating a pyramidal form. The bark becomes deeply ridged at about 25 years old. Sweetgum makes a nice conical shade tree for large properties when it is young, developing a more oval or rounded canopy as it grows older as several branches become dominant and grow in diameter.

Be careful when locating sweetgum as a street tree since its large, aggressive roots may lift curbs and sidewalks. Plant trees 8 to 10 feet or more from curbs. (Much of the root system is shallow.) The 1-inch round fruit may be a litter nuisance in the fall; people could slip and fall on the fruit on hard surfaces, such as roads, patios, and sidewalks.

The tree should be planted in soil with a pH of 7 or less. Chlorosis is often seen in alkaline soils. The seeds provide food for wildlife and will often readily germinate in shrub and groundcover beds, requiring their removal to maintain a neat landscape appearance. Although it grows at a moderate pace, sweetgum is rarely attacked by pests, and tolerates wet soils. Trees grow well in deep soil, and poorly in shallow, droughty soil. It is native to bottomlands and moist soils and tolerates only some (if any) drought. Existing trees often die back near the top of the crown, apparently due to extreme sensitivity to construction injury to the root system, or drought injury. The tree leafs out early in the spring and is sometimes damaged by frost.

The cultivar ‘Rotundiloba’ is fruitless. The leaves have rounded tips on this variety, and turn deep purple in the fall. It is hardy to zone 5b. The leaves of ‘Burgundy’ turn bright red-purple in the fall, and this variety is hardy to zone 6. In the fall, leaves are held on the tree longer than the species. The cultivar ‘Moraine’ is the most cold hardy cultivar known today. The star-shaped leaves turn bright red, purple, yellow or orange in the fall, and it is hardy to zone 5. It is the “smallest” of the cultivars with a mature height of 60 feet and a spread to 40 feet.

Is everyone having a bad clematis season? Why won’t the flowers get the normal size?

Clematis vines need lots and lots of water. That being said, they also need excellent drainage. This summer, Michigan had some periods of very hot scorching temperatures. Clematis need extra water during these hot times. If you have sandy soil, mulching and/or amending the soil is a must or it is difficult to provide enough water to the plant roots. (Remember to keep mulch from touching the base of the plants.) If clematis vines have to compete with deep-rooted trees or other plants, they may not receive enough water. If vines are starved for water, flowering and flower size can be reduced.

Shading the base of clematis is also necessary. Use plants like groundcover or hostas that do not have deep roots. Clematis vines also like to grow behind shallow-rooted shrubs or even come up through and over the shrubs. While the base should be shaded, most of the plant should climb into the sun. In fact, most vines need 6 to 8 hours of sun per day. Did a nearby tree grow larger through the years? Have you added any hardscapes like a pergola or trellis that is now shading the plant?

Also, lighter colors (generally) can take more direct sunlight than darker deep purples and reds, since dark colors absorb the light. The dark colors can suffer in bright sun and 90-degree heat, affecting flower production and size.

Clematis vines are heavy feeders, especially in spring and during flowering. Fertilizers with low nitrogen and high phosphorus are best for flowering. Watch to make sure that nitrogen fertilizers broadcast on the lawn aren’t getting near the vines. High nitrogen fertilizer will make nice leaves, but smaller or less flowers.

Some clematis need pruning and others don’t. Pruning at the wrong time or too severely can affect the blooms. In spring, wait until you see the first new shoots. If they come out of the ground, the plant blooms on new wood and should be pruned to about 12 to 18 inches from the ground in April. If the growth comes out of the nodules on last season’s vines, it is said to bloom on old wood. This type doesn’t have to be pruned. However, if they are getting weak at the top, or flower production is suffering, you can cut the vine back by a quarter to a third of its height. You may lose some bloom this year, but it will strengthen the vine overall.

Lastly, when is the last time you had your soil tested? Even if you have had it tested before, soil tends to revert to its natural state. If you have added amendments, it is good idea to check every few years to see what is happening in the soil. Maybe some critical nutrients are lacking that a soil test will point out. It will also tell you the soil pH (clematis like it slightly alkaline), and even recommend fertilizer percentages to add.