Dear Master Gardener: When should I put my hummingbird feeder away for the winter? I’m tempted to do it now because of all the bees and wasps around it.

Answer: Ruby-throated hummingbirds begin to migrate south for the winter from mid-August through the end of September. Sometimes you will see stragglers still in October. Keep your feeder up until you haven’t seen any hummingbirds for several weeks.

It’s important to avoid a hummingbird feeder with any yellow trim on it because it attracts wasps and bees. You can also find feeders that have bee guards and will not drip sugar water, which attracts them.

Related: Ask the Master Gardener: Add water when clematis plants are browning from the bottom up

Dear Master Gardener: When should I bring my tropical hibiscus in for the winter?

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Answer: Bring your hibiscus in if the outside temperature is going to fall below 55 degrees. First, spray the topsides and undersides of the leaves with the hose to knock off any insects. I put a systemic insecticide in the soil of all my houseplants. Place your hibiscus in a warm area (65-75 degrees is best) that is not drafty (they don’t tolerate fluctuating temperatures very well). They need very bright light to bloom indoors, so place them in a west- or south-facing window that has at least 4-5 hours of bright direct light. Keep the soil relatively moist but not saturated and allow the soil to dry out a little between watering. Never let the soil dry out to the point where the plant is wilting. Periodically wash off the foliage because a hibiscus is prone to getting aphids and spider mites. If you do get either one of those insects, use an insecticidal soap or insecticide/miticide labeled for use on hibiscus.

Related: Ask the Master Gardener: Moving flowers indoors before first frost

Dear Master Gardener: When and how should I plant daffodil bulbs?

Answer: Narcissus (daffodils and jonquils) got its name from Greek mythology. The handsome Narcissus fell in love with his own reflection in a pool of water and drowned as he tried to embrace himself. Legend has it that daffodils grew up at the site where he died so the genus was named after him. Narcissus bring a cheery, welcome color to spring gardens and September is the month to plant them. Drifts of 12 or more bulbs of one variety make the most impact. Plant the bulbs so the top (pointed end) is at least two times as deep as the bulb is high. Exactness isn’t critical — they will adjust. If you have sandy soil, they can be planted a little deeper. Space them according to the package directions and water well. And the good news is, deer, rabbits, and squirrels usually leave daffodils alone!

Related: Ask the Master Gardener: Oleanders can be houseplants, but be wary of their toxicity

Dear Master Gardener: Can I divide my daylilies now and how should I do it?

Answer: Yes, daylilies (Hemerocallis) can be divided now. Dig up the entire clump with a spade and shake off the soil. Cut the foliage back to a height of 6 to 8 inches to make it easier to work with the clumps. Next, carefully pull the clump apart; you may need to use a sharp knife (a hori-hori gardening knife is a great tool) if your clumps are large and dense. Make sure to have two or three fans of leaves and a good root system in each division. Replant the divisions as soon as possible. The crown of the daylily (where the roots and leaves meet) should be about one inch below the soil surface. Water thoroughly. The divided daylilies may not bloom well for a year or two.

Related: Ask the Master Gardener: Gardeners experiencing common tomato disorders

Dear Master Gardener: Should I cut my shrub roses back soon?

Answer: One of the advantages to shrub roses is that they require very little pruning. Do not prune shrub roses (or any other shrub) late in the season because it will encourage new growth, which will die back during severe winters. Spring is the time to prune shrub roses. That is the time to cut out dead wood, cut out inward growing or crossing canes and/or shape the plant.

Related: Ask the Master Gardener: It's easy to save seeds for use next year

Dear Master Gardener: Can I divide my Karl Foerster feather reed grasses in the fall? Should I cut my grasses down now or wait until spring?

Answer: Calamagrostis “Karl Foerster” can successfully be divided in the fall, but most other grasses respond best to spring division. Cutting back grasses in the fall, especially younger plants, may result in winter injury and the beauty of the plants in the winter landscape is lost. Older grasses that aren’t growing well in the center especially need to be rejuvenated by being dug up, divided, and replanted. In late winter or early spring, before new growth starts, cut back grasses to the ground to remove the previous year's growth. If the plants are not cut back, spring growth can be delayed and large plants will look unattractive throughout the year. “Karl Foerster” begins to grow very early in spring and can be cut back in March or early April.

Related: Ask the Master Gardener: Curcuma plants can offer a spectacular display

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 umnmastergardener@gmail.com 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.