Ask the Master Gardener: Stink bugs year-round pests in Minnesota

Stink bugs overwinter in Minnesota as adults in a hibernation-like state in woodlots, houses, sheds and garages. Adults may emerge as early as March and April and produce offspring in June.

Halyomorpha halys, also known as the brown marmorated stink bug (BMSB), is an insect in the family Pentatomidae that is native to China, Japan, the Koreas, and Taiwan.
Hectonichus / Wikimedia Commons

Dear Master Gardener: I am still finding those ugly stink bugs in my home in the Twin Cities area. Do they stay in Minnesota for the winter? Do they damage plants?

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Answer: The brown marmorated stink bug (BMSB) is a more recent pest to Minnesota that invades our homes in the winter, along with Asian lady beetles and box elder bugs. Yes, according to the DNR, brown marmorated stink bugs overwinter in Minnesota as adults in a hibernation-like state in woodlots, houses, sheds and garages. Adults may emerge as early as March and April and produce offspring in June. They feed until September and October, when populations usually peak, and then seek overwintering sites. There are native stink bugs and other species which are sometimes confused for the BMSB. Some of those look-alikes are predators that help us manage pests, but unfortunately the BMSB is a problem for a wide variety of fruits and vegetables.

Dear Master Gardener: I know I should prune my apple trees soon, but the snow is so deep I don’t know if I can get to them. When and how should my apple trees be pruned?

Answer: The best time to prune fruit trees is late winter or early spring when it will least affect your tree’s health. Prune apple trees when the coldest weather is past because if extremely cold temperatures occur after pruning it can lead to a slight, short-term reduction in winter hardiness and winter injury. It is preferable to prune before new growth has begun. Keep pruning to a minimum, especially with young trees because excessive pruning will delay or reduce fruiting and create too much leafy growth. The University of Minnesota recommends removing any diseased, broken, dead or downward-growing branches. If two limbs are crossed, entangled, or otherwise competing, remove one of them completely at its base. Remove any limbs along the trunk that are bigger in diameter than the trunk. In addition, remove suckers and water sprouts that grow straight up. Make pruning cuts close to the branch collar at the base of the limb.

Dear Master Gardener: I have a blue Echeveria and some of the bottom leaves have turned brown and crispy but the rest of the plant is beautiful and healthy. Am I doing something wrong? Also, I have two stems that have shot up from the center rosette and are going to bloom but they are bending over. Is that normal or a watering issue?


Answer: If your Echeveria is healthy and growing well, there is no need to worry about a few dried-up bottom leaves. It is normal for the lower leaves on many succulents, especially the rosette type, to occasionally turn brown and crispy and fall off. You can also remove them to clean up the plant. My blue-colored Echeveria bloomed in the fall and is about to bloom again. The flower stalks do curve and the bloom dangles. When it blooms it is a very pretty pink with an orange interior. With its blue leaves and dainty, dangling flowers, it’s a very beautiful plant!

Dear Master Gardener: I bought a Venus flytrap but I’m not sure there will be enough bugs in my house in the winter to feed it. Do they have to have insects to survive?

Answer: The Venus flytrap is a novelty houseplant that is native to the Carolinas. The nutrients they gain from catching and digesting insects will supplement their diet and benefit the plant’s development, but are not necessary for its survival. Like all other plants, the Venus flytrap makes its own food through photosynthesis. In their native environment they grow in the sun, which brings out the red coloring inside their leaf traps. If grown without sunlight, the plant will probably be green only. Never let this plant lack moisture. This is one plant that doesn’t need drainage! Never fertilize your Venus flytrap.

Dear Master Gardener: My spider plant has at least 15 babies. For the health of the plant should I remove any? How should I propagate the babies?

Answer: The spider plant is a popular houseplant because it is easy to grow and almost always produces new plants. You can either leave the plantlets on to create a very full look or detach them to produce new plants. Leaving them on does not affect the health of the plant. Spider plants are easy to propagate. At the end of long stems, called runners, miniature plants, called plantlets, will develop following flowering. Plantlets often form short, white aerial roots while still attached to the parent plant. Do not remove a plantlet from the parent plant until it has roots. After roots have developed, cut and remove the plantlet from the parent plant and place it in a pot. If you want to speed up root development, you can pin the plantlet down in another pot with soil and wait for the roots to form (this may take two to three weeks). A professional potting soil containing sphagnum peat moss with little to no perlite is best.

Dear Master Gardener: I was at a friend’s house last summer and he had lights shining up in some trees and it was a beautiful effect. Is there a way to do it and does it affect the tree?

Answer: You can illuminate beautiful areas of the yard by placing a fixture at the base of a tree’s trunk and shining it up towards the tree. By doing this, you are able to capture the beautiful branches and leaves above. Uplighting can be quite stunning if you have a tree with unusual branching or lovely bark. When placing the lighting fixture try to make it as unobtrusive as possible. The goal is to have a soft, subtle glow that is natural and provides ambiance. By placing lights in the right place and directing the glow towards the tree’s branches, you can create a dramatic effect to both your yard and tree. No, it does not negatively impact the tree.

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 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.

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