Dear Master Gardener: Last night we turned on our outdoor lights and saw a dozen or so flying squirrels around our bird feeder. Is this unusual?
Answer: No, it is quite common — but because flying squirrels are nocturnal, most people never see them. There are two kinds of flying squirrels found in Minnesota, the southern and northern. The northern is somewhat larger and heavier than the southern. Here in central Minnesota the habitats overlap. Flying squirrels do not actually fly. Rather, they glide from post to post, sometimes traveling over 100 feet, though most glides are 20-30 feet. Folds of skin stretching from the squirrels’ ankles to wrists can be stretched taut and form planing surfaces.
The squirrels are about the size of a chipmunk; 9-11 inches long (including tail) and weigh 2 to 3 ounces. Their fur is dense, soft and silky, grey-brown on the back, and white on the underside and tail. Their eyes are large and ringed with black, much like a raccoon. They nest in tree hollows and leaf nests and feed on fruits, grains, nuts, insects, and small birds. They are very fond of bird feeders. They do not hibernate and have mild dispositions.
Dear Master Gardener: Some of my houseplants are looking sickly. I think they have bugs. What are the most common pests of houseplants and what do they look like so I know how to treat them?
Answer: Three common houseplant pests are aphids, whiteflies and spider mites. Following is a description of them and what you can do to get rid of them.
Aphids are small (1/16 – 1/8 inch), nonwinged, green insects with pear-shaped soft-bodies that cluster on the buds, young stems, and leaves of plants. Aphids pierce plant tissue, suck sap, and excrete a sticky honeydew substance. They stunt the plant’s growth and cause the leaves to curl, discolor, and die. Plants that are susceptible to aphids are: dieffenbachia, ferns, hibiscus, and ivies. To control aphids, wash the plant with warm soapy water then rinse with clear water. Neem oil, insecticidal soap, or an insecticide specific to aphids may also be used.
Whiteflies are not flies; they are more like scales, mealy bugs, and aphids. The adult whiteflies are tiny (1/16 inch) and the young ones are even smaller. They are pale in color; therefore, difficult to see. Whiteflies flutter up when you water or handle a plant they are on. They suck the plant sap with their piercing-sucking mouthparts, which cause infested leaves to yellow and drop, reducing the plant’s health but usually not killing it. These insects are more of a problem in greenhouses than homes. Susceptible plants include begonia, coleus, and ferns. Washing the leaves, treating them with neem oil, or for more serious cases, pyrethrum or bifenthrin may be used to control these pests.
Spider mites are one of the most serious houseplant pests because without treatment they multiply quickly, defoliate the plant, and kill it. They are almost impossible to see with the naked eye, so to determine if your plant has mites, place a sheet of white paper under the leaves, tap them, then check to see if there are tiny green, red, or yellow specks the size of pepper grains crawling around. Spider mites thrive in warm, dry conditions and usually make their way indoors in summer or on Christmas greenery or trees. The first sign of a spider mite problem is typically a mottled or pin-prick yellow discoloration on the undersides of leaves. Asparagus fern, cacti, ivies, and schefflera are susceptible plants. Control options include washing, insecticidal soap (applying every seven-10 days), or bifenthrin.
Dear Master Gardener: Is now a good time to start sowing seeds indoors? Do I need special grow lights or can I use fluorescent shop lights?
Answer: There are some seeds that are slower to mature and need to be started earlier than others. The goal is to sow seeds so they are ready to plant after there is no threat of frost, which for us in north central Minnesota is Memorial Day. There are some seeds that can be started in February. Geraniums, pansies, violas, wax begonias, leeks, and onions need 14-15 weeks of indoor growth. Browallia, dusty miller, fountain grass, impatiens, larkspur, lobelia, nemesia, stocks, torenia, and celery need 12-13 weeks. It is best to refer to the directions on your seed packets to find out how long the germination is, whether the seeds need any other treatment before planting, and how deeply you should plant the seeds.
To start your seeds, use a growing medium that is light, porous, and sterile. Commercial seed-starting mixes are an excellent choice. If your potting mix is dry, you will want to moisten it before planting your seeds. Ideally, seeds should be planted in small, individual containers that have drainage holes, with a single seedling in each container. Onions and leeks, started from seed, are an exception, and can be started in a large flat. Covering your containers with domes or plastic wrap will help keep the soil moist and humid. You can use a spray bottle with warm water to mist the soil when it is needed. Because you want to keep your soil warm, a windowsill is a poor place for germinating seeds because it is too cold. For some seeds, the top of a refrigerator works well. You can also purchase electric heating mats, which are made for starting seeds. Keeping a continuous heat source from underneath can be very beneficial to seedlings. When the plants emerge from the soil and reach the plastic cover, you can remove it. After the seedlings get their first few leaves, feed them once a week with a water-soluble fertilizer at one-fourth strength.
You do not need to purchase special grow lights; fluorescent shop lights work very well. Hang the lights from chains to make it easier to raise them as the plants grow. Place the lights as close as two inches, but no more than four, to the tops of your plants for 14-16 hours each day. Because many plants need a dark period each night to develop properly, do not leave the lights on continuously.