Answer: Since your plants are turning brown from the bottom up, but the upper part is still green and you have flowers, it sounds like they may not be getting enough water. Clematis are extremely thirsty plants and need a tremendous amount of water. It is virtually impossible to overwater them. If it was Clematis Wilt (which is about the only disease they get) you would have wilted, darkened leaves and stems as well as plant dieback. Water your plants at the base very well for the rest of the season. Clematis have extensive root systems that go down deep and spread out wide. They also like their root system cool, so if you don’t have mulch around them that would also help. Just be very careful not to have mulch touching the stems — push any mulch away from the stems several inches out. I also plant some other perennials or ground cover around them to help shade the roots. There is an old adage about clematis: “They like their heads in the sun and their feet in the shade.”
Related: Ask the Master Gardener: Oleanders can be houseplants, but be wary of their toxicity
Dear Master Gardener: Although we got some rain last weekend, the ground still seems dry. Should I bother seeding the bare spots in my lawn?
Answer: The best time to seed a lawn is late summer/early fall (under normal circumstances). With the severe drought we are in, many cool-season lawn grasses have gone dormant. To tell whether your grass is dormant or dead, observe how it reacts to a rainfall of one inch or more (if we’re so lucky). A few days after the rainfall if there is no green on young shoots, most likely the grass has perished.
Go ahead and keep seeding over the next three weeks. Seed is fairly cheap and easy to apply. Seed thin or bare spots as soon as possible to take advantage of the cooler temperatures and potential rain that is forecasted for the upcoming week.
Another riskier option for reseeding bare spots or thickening up a thin lawn is to do dormant seeding, which is done late October or the beginning of November. The theory is that seed will stay “dormant” due to the cold soil, then begin to germinate as soon as the soil warms up in the spring. This method can give you a head start of several weeks in getting the lawn established in the spring. Dormant seeding usually works best when it snows several inches on the newly seeded areas and the snow remains until spring. Put down the seed before the ground freezes, but is still cold enough so germination of the grass seed will not occur until next spring. Water the area thoroughly and leave it until next spring.
Related: Ask the Master Gardener: Gardeners experiencing common tomato disorders
Dear Master Gardener: When should I divide and move my peonies?
Answer: Peonies do not like to be disturbed; however, if you want to divide and move your peonies it can be done in September. Dig up and lift the peony clump and divide it into sections with a sharp knife or shovel making sure to have at least three eyes per division. Keep in mind that the smaller the division, the longer it will take your peonies to bloom again. Cover the peony roots so the pink buds (eyes) are pointing up and are approximately 1 ½ to 2 inches below the soil line. If they are planted too deep, your peony will never bloom. Plant them in full sun, in well-drained soil, and space them four feet apart. It is important to replant divided peonies immediately.
Related: Ask the Master Gardener: It’s easy to save seeds for use next year
Dear Master Gardener: I dread the fall onslaught of box elder bugs and Asian lady beetles. What can I do to ensure they do not get into my home?
Answer: According to Jeffrey Hahn, professor of entomology at the University of Minnesota, the multicolored Asian lady beetle has become very troublesome in Minnesota. These insects cluster around buildings in large numbers during the fall as they search for protected sites to overwinter. Although they are a nuisance, the good news is that they do not infest wood, destroy fabrics, eat your food, damage other property, sting, or carry diseases. They do however smell bad and do bite. Like Asian lady beetles, box elder bugs try to move into homes in the fall in search of an overwintering site. They, too, are harmless to property and people but can stain your interior with their excrement. To keep unwanted insects from moving into your home, September is a good time to check the exterior of your house for cracks and spaces where they could enter, and caulk or make any necessary repairs to seal your house. Seal around windows and doors, and where utility wires and the dryer vent enter your home. If you find them in your home the best removal is to vacuum them up. A spray bottle filled with soapy water can be used to spray them if they’re napping on your south wall on a sunny day.
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Dear Master Gardener: Which perennials can be divided now?
Answer: The following perennials can be divided in late summer/early fall: Asiatic lilies, bearded iris, daylilies, Jacob’s ladder, peonies, tall phlox, and Siberian iris. All of them, with the exception of Asiatic lilies and bearded iris, may also be divided in early spring.
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Dear Master Gardener: I planted Brussels sprouts for the first time this year, how do I know when to harvest them?
Answer: To speed up the development of the sprouts, remove the growing tip about three weeks before harvest. Do not pluck off the leaves of the plant as it is growing — the more leaves on the plant the more energy they produce and the bigger the sprouts will grow. Harvest the sprouts from the bottom up when they are about an inch in diameter and firm. The cooler temperatures, even a light frost, result in better flavor.
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You may get your garden questions answered by calling the new Master Gardener Help Line at 218-824-1068 and leaving a message. A master gardener will return your call. Or, emailing me at [email protected] and I will answer you in the column if space allows.
University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. Information given in this column is based on university research.