September "In The Grow" - Indiana Yard and Garden - Purdue Consumer Horticulture

September “In The Grow”

Q. Although I am aware of the need to cut back or pinch mums until about the Fourth of July, I need your advice about other flowers, namely daisies, black-eyed Susans, impatiens and petunias. Should all of these be pinched, too, and if so, when?

For some time now, I have noticed so many daisies and black-eyed Susans in beautiful clumps standing so stately. As soon as mine are blooming nicely, they begin to droop and fall over. I seldom water them, thinking that causes them to fall over. Basically, I have the same problem with impatiens and petunias. They become very leggy. I have cut them back some, yet they never seem to flower much after that. I see beautiful clumps and pots of these solid flowers that do not appear to ever have been cut back.

I’m wondering if any or all flowers that come up the following year should just be cut back. Thank you for your help. -Bonnie Shelton, Lafayette, Ind.

A. Pinching helps plants branch more and, therefore, become more full and bushy. Petunias and impatiens always benefit from some pinching throughout the growing season. Any annual flower that becomes leggy can be pinched back. You sacrifice the flowers in the short run but eventually get the look you desire.

There are dozens of cultivars of black-eyed Susans and daisies on the market. One possibility for the height of your plants is that you have seedlings or a taller cultivar, while the fuller clumps you see are cultivars that have been bred to be short and stocky. Another possibility is a lack of light. Often, plants will stretch the space between leaves in an attempt to reach sunlight.

If you choose to pinch these plants back, I would do it only for the early part of the season. Your plants then will be fuller but flower later than usual. Provide proper water and fertilizer throughout the growing season.

Q. My children and I are growing pumpkins for the first time. The plants are big, strong and healthy and have had probably 20-25 blooms during the past four to six weeks. However, with all these blooms, we have only one pumpkin. Is there something else we should be doing? Thank you. -Pamela Heaton

A. Poor pollination leads to poor fruiting. Insects, especially bees, pollinate the flowers. Cold, rainy weather can reduce bee activity, as can improper use of insecticides. Pumpkins produce male and female flowers. Usually, the first flowers of the season are male flowers, and there are no female flowers available to pollinate. In the time that has elapsed since you wrote, perhaps more fruit has set on your vines as more female flowers opened.

Q. I have two miniature rose bushes that have grown quite a lot this summer. How do I care for them in the fall and winter, like pruning and shelter from the cold. Thanks. -Dorothy Feller, Corydon, Ind.

That’s a great big question! Water your roses before the ground freezes if fall rain is not adequate. Then, winterize them in late fall after a hard frost when the plants are dormant. Remove old leaves, dead stems and other debris. Tie the canes together by tying twine spirally up and around the plant. Then, mound the base of the soil to a depth of 12 inches. Additional mulch, such as bark chips, chopped leaves or straw, can be placed on top for additional insulation. A bushel basket with the bottom removed or a wire cage can be placed around the plant to hold insulation in place.

Styrofoam cones are a popular way to protect roses but shouldn’t be used as a substitute for mounding. For best protection, mound soil 6-8 inches deep before applying the cone. Some cones have a removable lid to allow heat to escape. If not, punch or slice holes in the top to prevent heat and moisture buildup. Secure the cone in place with rocks on top and soil around the base.

Q. I have a river birch, which was planted two springs ago. In the spring, it developed a powdery mildew, which I believe I successfully treated; however, it still appears wilted and has lost leaves. Some of the branches look almost black instead of a healthy woody color. Some leaves now appear to have some type of a scale-type look to them (bumpy; almost looks like insect eggs but are part of the leaves). I have deep-watered the tree several times this summer, but it still looks sad. I would appreciate any advice. Thanks. – Bob Hurm

A. It even SOUNDS sad! River birch usually are easy to grow. Water and fertilize to keep the tree as vigorous as possible and take a sample to your county extension office. Make sure you include the black branches, as well as the bumpy leaves. You may have both insect and disease problems, but the tree could outgrow one or both of the problems. Therefore, don’t start spraying anything until you have a proper diagnosis.

Share This Article
Disclaimer: Reference to products is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in these articles assumes full responsibility for their use in accordance with current directions of the manufacturer.
Indiana Yard and Garden – Purdue Consumer Horticulture - Horticulture & Landscape Architecture, 625 Agriculture Mall, West Lafayette, IN 47907

© 2024 Purdue University | An equal access/equal opportunity university | Copyright Complaints | Maintained by Indiana Yard and Garden – Purdue Consumer Horticulture

If you have trouble accessing this page because of a disability, please contact Indiana Yard and Garden – Purdue Consumer Horticulture at | Accessibility Resources