Ask a Master Gardener: How to grow citrus in Minnesota

Dear Master Gardener: I just learned recently that oranges and lemons can be grown indoors in Minnesota. I would love to grow my own citrus fruit. How do I do it?...

Dear Master Gardener: I just learned recently that oranges and lemons can be grown indoors in Minnesota. I would love to grow my own citrus fruit. How do I do it?

Answer: Yes, certain oranges and lemons can be grown as houseplants, but you will be disappointed if you expect to harvest large quantities of fruit such as you would find in a supermarket. Commercial fruit trees are too large to grow indoors and could not survive our Minnesota winters. The most commonly found indoor citrus trees are Calamondin oranges (Citronfortunella mitis) and Meyer lemons (Citrus x meyeri). Less popular but often available are tangerines (Citrus reticulata) and Satsuma oranges (Citrus reticulata Blanco), which are really very sweet tangerines whose blossoms are especially abundant and fragrant. Calamondin oranges are small and sour so are not particularly good for eating out of hand. They do, however, make good marmalade and are colorful and fragrant plants. Meyer lemons are milder and sweeter than commercial lemons, are not abundant producers and need annual pruning to keep their size manageable. All citrus trees grown indoors have similar growth requirements. Indoor temperatures should be around 65 degrees, up to 10 degrees lower at night. They prefer a south-facing window with several hours of direct sunlight. They benefit from being set outdoors from about May-September, transitioning to a couple of weeks in the shade both going out and coming in. They are acid-loving plants so their soil requirements include plenty of peat moss. A mixture of 1/3 sterile potting soil, 1/3 peat moss and 1/3 perlite or vermiculite would be ideal. Fertilize plants at half-strength once or twice a month when they are actively growing (about April through September) with a fertilizer formulated for acid-loving plants. They need regular watering and wilt easily. Make sure they do not sit in water. Indoor citrus make attractive houseplants and have the added benefit of fragrant blossoms and colorful and interesting, though not abundant, fruit. Sometimes a plant will have blossoms and fruit at the same time. Just don't plan to send boxes of Minnesota fruit to friends in Florida and California.

Dear Master Gardener: My grandmother had some bleeding hearts growing in her garden. Do they grow up here and if so, should I plant them in the sun or shade?

Answer: Bleeding Hearts (Dicentra) are hardy to zone 3 (40 degrees below) and are a wonderful addition to the shady garden. They are easy to grow and have lovely blue-green foliage with distinctively shaped flowers that dangle from arching stems. Plant them in light to full shade, ideally in a woodland garden. They grow best in loose, organic soil that has been amended with compost, rotted manure, leaf mold or peat moss and is kept evenly moist.

Dicentra cucullaria, also known as Dutchman's breeches, has lacy foliage and small white flowers tipped yellow. It goes dormant after blooming in spring. Dicentra formosa "Langtrees" (Pearl Drops) and Luxuriant, which is also known as Western Bleeding Heart, blooms in spring and often reblooms throughout the summer if deadheaded. "Luxuriant" is vigorous and flowers freely. Dicentra-Hearts Series was bred in Japan. A variety that does well here is "Burning Hearts," which has deep rose red flowers and striking blue-gray foliage. The Hearts Series, like other fringe-leaved Bleeding Hearts, bloom profusely during late spring and early summer and may bloom off and on throughout the rest of the season. Dicentra spectabilis is the Common Bleeding Heart with pink flowers. "Alba" is the pure white variety, which isn't as vigorous as the pink varieties. In our climate, the Common Bleeding Heart blooms from late spring into early summer.


Dear Master Gardener: Our daughter is getting married at our home next summer and the grass in the area where we would like to have the reception looks quite bad. We would like to start a new lawn from scratch and have sandy soil. Do you recommend seeding or laying sod to have a wedding-worthy lawn?

Answer: That is a common question for those who want to establish a new lawn and there are advantages and disadvantages to both. The main difference between seeding and sodding is the time necessary for developing a mature or durable turf. Basically, sodding is transplanting a mature turf that has been cared for by a professional. There are many variables when it comes to seeding, which makes it difficult and often unsuccessful for a homeowner.

The advantages to seeding rather than sodding are: more grass types and varieties from which to choose, stronger root system initially, and less expensive. Disadvantages include: takes longer to establish and moisture is critical, and for best results seeding should be done in late summer and early fall.

The advantages to sodding are: rapid establishment, relatively weed-free, good for slopes or areas prone to erosion, and it can be laid any time during the growing season. The disadvantages are: less selection of grass types, which could be an issue if you have shade (most sod grown in Minnesota is a mixture of Kentucky bluegrass) and it is more expensive.

Whether you seed or sod, preparation of the soil is extremely important and will simplify future maintenance. You may want to get your soil tested first to find out if the soil needs amending. Sandy loam, which is mostly sand with some silt and clay, is the best type of soil for growing turf. If you add "black dirt," which is usually made up of silt and clay, carefully incorporate it into the native soil. If you need a large amount of fill to raise up an area, you may use good quality topsoil as long as it is less than 20 percent clay and free of herbicides. If your soil test suggests adding amendments, till them into the soil, then grade the area. You can use a roller to firm the soil slightly and now your site is ready for seed or sod.

If you decide to seed, the best time to seed is mid-August to mid-September as the conditions are more favorable for germination and growth and fewer weed seeds germinate at that time. You can seed in the spring, but the weeds that compete with grass germinate at this time, the root system doesn't have time to develop before the summer heat stresses it, and high summer temperatures often reduce the chance for success. If you decide to sod, buy it as fresh as possible and lay it as soon as possible, ideally within one day after delivery. Lay sod on slightly moistened soil, staggering the joints.

If you are interested in getting more ideas on how to get your landscape ready for the wedding you may want to attend the 2015 Garden Expo sponsored by the Crow Wing County Master Gardeners being held at Central Lakes College on Saturday, April 11. One of the 26 seminars being offered is "An Invitation to the Garden: How to Create the Perfect Setting for Entertaining". This seminar should appeal to anyone who wants to get information and ideas about getting their gardens and lawn ready for outdoor entertaining in general, but especially those hosting a big event, as the presenter will share photos and ideas about preparing for an outdoor wedding at their home. There will be 26 seminars offered at the Expo where you may get additional landscaping ideas and information that would be beneficial for hosting your big event.

February gardening tips:


• Spend some time this wintery month perusing seed catalogs and seed racks in stores and garden centers. Order seeds now to be sure you get what you want.

• Washing dust off houseplants will allow maximum light for photosynthesis. Either wipe leaves off with a damp cloth or set entire plants in the sink or shower and spray them.

• Pansy, impatiens, wax begonia, viola and snapdragon seeds should be started this month because they need extra time to mature to transplant size. It is too early to start most other seeds because they will tend to get leggy and weak.

• If you plant to start seeds indoors this year, start assembling supplies now. You will need pots, trays, fluorescent lights that can be raised and lowered, a timer and good potting soil.

• Check houseplants frequently for destructive insects. Cottony fuzz indicates mealy bugs; sticky, shiny honeydew suggests aphids or scale; pinprick discoloration means spider mites. See houseplant insect control on the University of Minnesota extension site on the internet.

• Roses are by far the most popular Valentine flowers. Consider other blooming plants as well, such as orchids, anthuriums, birds-of-paradise, or baskets of blooming bulbs.

Crow Wing County Master Gardeners are trained and certified volunteers for the University of Minnesota Extension Service. All information given in this column is based on research and information provided by the University. To ask a question, call the Master Gardener Help Line at 824-1000, ext. 4040 and leave a recorded message. A Master Gardener will return your call.

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