Ask the Master Gardener: Protect your garden by rotating your crops

It is important to avoid having plants of the same family in the same location in your garden for three or four years to avoid the buildup of shared pests.

Now is the time to trim spent cyclamen blossoms to promote blooming. Photo by Jennifer Knutson

Dear Master Gardener: Last summer my eggplant produced flowers but no fruit. Why?

Answer: First, I will address the importance of crop rotation in your vegetable garden. Eggplants are in the same family (Solanaceae) as tomatoes, potatoes, tomatillos, and peppers. It is important to avoid planting any of these in the same location in your garden for three or four years to avoid the buildup of shared pests. It helps to know which botanical family the vegetables or fruits you are planting fall under. For example, members of the Rosaceae family (strawberries) should not be planted after members of the Solanaceae family, and vice versa, because they are both susceptible to verticillium wilt disease. Plants in the Fabaceae (legume) family can be rotated to an area of your garden where plants that were heavy users of nutrients were growing because they will add nitrogen to the soil.

Related: Ask the master gardener: Winter sowing and growing in small spaces Tips for creating your own mini-greenhouses using milk jugs, potting soil, and setting it in the snow with this relatively new alternative to starting seeds under lights.
Although eggplants are related to tomatoes, they are much less cold tolerant. The overnight temperatures need to stay consistently above 55 degrees or they may suffer and never bear fruit. To improve pollination and fruit set you can move pollen from one flower to another with a soft-bristled paintbrush.

Dear Master Gardener: When my Phalaenopsis orchid is done blooming, how do I cut it back? Will it rebloom?

Answer: It depends. Of the commonly available orchids, the Phalaenopsis (moth orchid) is the only one that may rebloom from its old spike. Young or weak plants may not rebloom and some are not genetically capable of reblooming from the old stem. If it is a small Phalaenopsis, cut the stem to the base where it comes out of the leaves. If it is a larger one, you can leave the stem on and it may continue flowering, but the flowers are usually smaller. Sometimes people cut off the stem at the base and it blooms again in several months. Another option is to cut off the stem in between two nodes (the brown lines on the stem below where the flowers were) which will initiate flower production. It is very important to use a new straight-edge razor blade or sterilized pruner to avoid spreading a virus to your plant.


Related: Ask the Master Gardener: There are positives and negatives to winter bird feeding Dangers for birds eating from feeders in the winter include contaminated food, injury or disease.

February Garden Tips

  • Great Horned Owls begin nesting in January or February. Barred Owls nest in March. Take a walk by the light of the moon to listen for their unique calls. The Great Horned Owl has a low-pitched “Hoo Hoo” and the Barred Owl’s call is “Who cooks for you, who cooks for you all.” “Owl Moon” by Jane Yolen is a great book to read with children.

  • Start saving and washing out small yogurt containers for seed starting next month. Punch a few holes in the bottom for drainage.

  • Extend the bloom of your Valentine’s Day cut flowers by keeping them out of drafts, recutting the ends, and changing the water every other day.

  • Big, beautiful amaryllis blossoms are delightful in the dead of winter. Treat them as sun-loving houseplants. Put them outdoors in summer, fertilize them in spring and summer, and move them to slightly bigger pots as the bulbs get larger and develop offshoots. They should bloom annually for years to come.

  • The end of February through the end of March is a good time to have shade trees pruned. Unless the trees are still small and accessible, you may want to hire an experienced professional to do the job. Do not use pruning paint!

  • Check on your calla lily, dahlia, canna, gladiola, and tuberous begonia bulbs you are storing over the winter. It is not unusual for them to rot in storage, especially if they are not kept cool enough. Discard any that are soft and mushy.

  • Plant begonia tubers in a flat of peat moss or vermiculite now for bloom in June.

  • Start your seeds for impatiens, petunias, geraniums, leeks and onions at the end of this month. Pansies and violas can be started mid-month.

  • Increase your houseplant collection or share new plants with friends by propagating pothos, ivies, philodendrons, and other houseplants. Fill an oblong plastic bag with fresh vermiculite. Add water and seal the opening. Make small slits to poke cuttings into, then move the “pillow pack” to a bright location. When all cuttings root, open the bag and transplant them into containers of fresh potting soil.

  • If you have little insects that look like fruit flies flitting about your houseplants, you probably have fungus gnats. These larvae live on decaying matter in soil. Allow the soil to dry out between watering sessions. To get rid of adult fungus gnats, hang a yellow sticky trap nearby.

  • By the end of February, the days are getting longer and many houseplants are resuming active growth. Provide the nutrients they need by fertilizing them at half-strength every three to four weeks. Don’t fertilize if the potting soil is bone dry or you don’t see active growth.

  • If you are purchasing a flowering plant for Valentine’s Day, choose plants with a few open blossoms and a lot of healthy-looking buds. Protect them from the cold on the trip home by wrapping them very well. If flowering plants are exposed to cold drafts, they may drop their buds (bud blast).

  • Trim off spent cyclamen blossoms before they form seed heads to promote repeat blooming. Feel the soil and water if dry. Be sure the pot drains well.

  • When perusing seed catalogs, look for vegetable and flower cultivars with superior disease-resistance and make sure they will mature in our relatively short growing season.

Related: Ask the Master Gardener: Plenty to do for gardeners to keep busy in winter Research, indoor projects and preparation for spring are good options for gardeners in winter.

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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