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Mystery of the month
What should you do if you see your spring flowering bulbs emerging from the ground? The solution is at the bottom of this article.
Find the solution to our mystery at the end of this article.
Pests and diseases
Finish pruning woody plants by the end of March this year.
- Check chokecherries, sour cherries, plums, and other Prunus for black knot swelling on branches. Check apples, pears, and moutainash for fire blight.
- Prune at least six inches back into healthy wood to remove diseased tissue.
- Dip your pruners into a bleach solution between cuts.
- Take all infected branches out of the landscape and burn or bury them.
Read more on how to clean and disinfect gardening tools and containers.
Trees and shrubs
Tried tapping sugar or silver maples on your property? What about black walnuts? This year, tapping of maples and black walnuts started in late February in the southern half of the state. If you are further north, you may still be able to start tapping in early March.
The best conditions for sap flow are warm days and nights at or below freezing.
See our page on making homemade maple syrup.
Watch our Hort Shorts on YouTube for videos tapping black walnut and maple.
Flowers and other garden plants
Do not be tempted to uncover roses and other tender perennial plants on warm days in March. Removing mulch and other covers too early exposes plant crowns to unpredictable cold snaps that can damage them.
Keep most tender perennials covered until early to mid-April in the Twin Cities and mid- to late-April further north.
Iowa State University Extension has a great article on how to overwinter roses.
Houseplants
Start fertilizing any actively growing houseplants. The increase in day length prompts plants to start growing at a faster pace than they do during the shorter winter days.
Plants may also start taking up more water, so monitor the moisture of the potting mix and adjust your watering schedule accordingly.
Lawn
Check out the UMN Turfgrass Science Dashboard because March can be a tricky time of the year for our lawns.
If we get an early spring, summer annual grassy weeds like crabgrass may germinate at the end of the month. You can track this by looking at the turf dashboard for crabgrass germination. Otherwise, forsythia bloom time can closely resemble when crabgrass germinates. This information can be useful if you would like to put down a crabgrass pre-emergent herbicide.
Other tasks
Vent any outdoor greenhouses, cold frames, low tunnels, or jugs with plants in them on sunny days over 45F. The temperatures inside can be 30 or more degrees warmer than the temperature outside. If the temperature gets too warm and then dramatically drops at night, it can hinder plant growth.
Solution to the mystery of the month
You do not need to worry about snowdrops being exposed to cold temperatures as long as the temperatures do not drop below 0F. They can withstand cold temperatures without mulch or snow cover.
You may also see other spring-flowering bulbs emerging throughout the month. Most have adapted to the cooler temperatures and do not need to be covered with mulch or fabric when temperatures are at or above the high 20s.
Planting bulbs, tubers, and rhizomes has information on what to do in the spring.