Ask the Master Gardener: Eastern hemlock trees are very rare and need the right conditions to survive

Dear Master Gardener: Can we grow hemlock trees in this area?

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Answer: Eastern hemlock (Tsuga canadensis), also known as Canadian hemlock, is one of the rarest trees in Minnesota and on the state endangered list. According to the Minnesota DNR, the largest stand of nearly 5,000 trees was in southwestern St. Louis County. In 1912, about 8,000 railroad ties were cut from this stand, then the Moose Lake-Cloquet fire of 1918 destroyed almost all the rest, and what was left eventually died. Currently there are only about 50 mature trees remaining in all of Minnesota. Although the Eastern hemlock is rare in the wild in Minnesota, it is available in the nursery trade with many cultivars available. It is a beautiful tree, hardy to zone 3, but needs the right conditions to thrive. It does not do well in an urban environment and has a very low tolerance for polluted air and salt damage from roadways. It needs to be in a sheltered location protected from drying winds and grown in partial shade. These trees require rich, well-drained, acidic soil. The Eastern hemlock has soft needles and an upright, open habit of growth with a conical shape. The trees grow very tall, 40-60 feet tall, but there are shorter cultivars. Aurea grows to about 20 feet and has golden foliage when it is young, which then ages to green. Unfortunately, this tree has numerous disease and insect problems.

Dear Master Gardener: I found a lot of moths in my house that are small and whitish-tan in color. Will they put holes in my clothes?

Answer: The most common moth that will attack fabric is the webbing clothes moth, which will make irregular holes in fabric. A webbing clothes moth is approximately one-fourth to one-third of an inch in length and has buff-colored wings that are folded behind its back when at rest. These moths are usually found in dark areas of rooms. They feed on wool, fur, and other materials of animal origin. Typically, moths do not eat clothes made out of cotton or synthetics unless the fabric is stained with food or sweat. To prevent webbing clothes moths from causing any damage, regularly vacuum your rugs, carpets, baseboards, closets, and underneath furniture. Periodically check your clothes, especially woolens, for any signs of insect damage. Store out-of-season clothes in airtight, plastic containers, making sure to wash or dry clean them first.

Dear Master Gardener: I purchased a plant called Gold Dust and was wondering how big it will get and what kind of light it needs.

Answer: Gold dust plant (Aucuba japonica) is a dense, shrubby evergreen native to Japan and East Asia. It gets its common name from the yellow specks on its dark green, oblong-shaped leaves. Female Aucubas produce small purple flowers followed by red berries. This plant will grow three feet tall in a pot — larger in a planter. Prune it to keep it under control and make the plant bushier. Aucuba is a cool temperature plant — 60 degrees is ideal, so it will do better in a cool room versus a warm living room. Give it bright but indirect light — some east sun would be OK. Turn your plant regularly to expose all sides to the light. Never let the soil dry out completely.

Dear Master Gardener: Can I reuse my potting soil from last year?

Answer: Yes, as long as whatever you were growing in it was healthy. Add some compost or rotted manure, or some additional potting soil or slow-release fertilizer to get the nutrient levels back up.

Dear Master Gardener: I bought a Bromeliad recently at a local store, but it didn’t have any directions on how to care for it. When I unwrapped it, there was water in among the leaves at the base of the orange-colored flower. What is the best way to care for a Bromeliad and how long will the flower last?

Answer: Bromeliads are tropical plants in the pineapple family. The flower is actually a long-lasting, colorful bract. Bromeliads are easy, slow-growing houseplants that add a dramatic splash of color to our winter homes! In order to survive and grow well, bromeliads need warm temperatures (at least 60-70 degrees). Bromeliads that form a rosette-shaped reservoir at the base of the plant need to have the reservoir filled with water at all times, being careful not to let water soak the soil. Bromeliads are prone to root rot if the soil is kept wet, so make sure your plant drains well and never sits in water.

The colorful bracts will last anywhere from several weeks to several months. When the color fades, the bromeliad will slowly die. Don’t worry! The plant will send up several “pups” alongside the plant. When the pups are about one-third the size of the parent plant, cut them apart and pot them up to form new plants. It will take about three to five years for them to show color.

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.