Ask the Master Gardener: How to curtail the creep of Creeping Charlie – Brainerd Dispatch

Dear master gardener: I have more Creeping Charlie than grass on my lawn! Is there anything I can do this fall to kill it?

answers: You’re not alone – it looks like it’s going to be a great year for good old Charlie. An evergreen perennial in the mint family, Creeping Charlie isn’t fussy—it’ll grow just about anywhere. She loves moist soil and either sun or shade. It spreads to the ground with long stems, also called stolons, which regularly sprout leaves and then drop roots at each of these stem nodes. You can run a contest to see what the longest stem you can pull is, but be warned that any node with remaining roots will send out new runners and you’ll be back playing your game in no time. I think it’s a positive that Charlie is green first thing in spring and has purple tubular flowers that pollinators like, but it will outperform your lawn grass for water and nutrients.

However, fall is the perfect time to spoil your Charlie. Foliage herbicides containing triclopyr or dicamba seem to be most effective. Read the package label to make sure it works on Creeping Charlie and apply as directed. Spray the leaves just enough to wet them – they will absorb the product and transport it to the roots, killing them and preventing the plant from storing nutrients for spring growth. The plant needs to be actively growing for this process to work, so don’t wait too long. Some products recommend a second application 10 days later. As always, use herbicides with caution so as not to affect nearby “good” plants.

Dear master gardener: I bought a bag of tulips last month but didn’t have time to plant them. It is too late?

answers: No, it’s the perfect time to plant spring onions. Hardy bulbs, which can be left in the ground year after year, need a cold spell to bloom the following spring. That’s why we plant them in the ground in autumn. For us in northern Minnesota, mid-September to mid-October is the ideal planting time. Tulips can actually be planted at the latest – as long as the ground can still be dug up. Choose firm tulip, daffodil, iris, muscari, allium, snowdrop, and crocus bulbs that have a papery skin and are not soft or moldy. The roots begin to grow until the ground freezes and may emerge before all the snow is gone by next spring. If only the leaves are showing you should still get flowers, but if we get a hard frost after the flower bud has appeared the flower may be stunted or not open at all. Planting near the house foundation is likely to induce an earlier appearance. Choose sunny, well-drained locations for your bulbs.

Plant bulbs in large groups for the greatest impact. If you want a natural look, toss the bulbs in the air and plant them where they land. Daffodils are generally ignored by deer and rabbits. A word of warning: Tulip bulbs are like candy to squirrels. Don’t leave any of the paper skins lying around – this just advertises that something tasty is nearby. Almost every year I have tulips popping up in different places – and it wasn’t me who moved them! Placing chicken wire over all new plantings will help minimize critter digging.

• Pick tomatoes and peppers and bring them in as soon as frost threatens. Peppers do not continue to ripen, but are tasty at any stage of development. Tomatoes ripen well indoors. To ripen them, spread them out of direct sunlight. Do not refrigerate them or they will lose their flavor.
• Plant tulips, hyacinths, and mini daffodils in shallow containers to force winter blooms. Place the containers in a cool, dark place for about three months. After this cold treatment, place the bulbs in bright sunlight for three to four weeks. Bulbs started mid-month should bloom around mid-February.
• Protect hybrid teas and other non-hardy roses here around the middle of the month. Waiting much longer can be a gamble because hives will be damaged or killed if temperatures drop below 20 degrees. Piling soil over the crowns or tying sticks together and then tipping them into trenches is more labor intensive but more effective than using Styrofoam rose cones. In fact, cones are no longer recommended as they can trap moisture and cause fungal problems. Rake leaves over the base of hardy roses.
• Cover the strawberry plants with clean straw to protect the crowns after several nights of temperatures in the mid-20s. This allows the plants to go dormant.
• Brassica vegetables such as kale, turnip greens, broccoli, and Brussels sprouts develop a milder flavor when exposed to frost before harvest.
• Continue watering your lawn as needed to minimize winter water stress on lawn grass. Gradually reduce the mowing height to two and a half inches until the grass comes to rest. Long grass left lying in winter folds up under the weight of the snow, forming wet pockets that encourage snow mold growth. To minimize snow mold, rake up thick mats of leaves and compost. If there aren’t many leaves, go ahead and mow them in.
• Don’t panic if your evergreen trees and shrubs lose their innermost needles in the fall – it doesn’t mean they’re ill. It is normal for the inner growth to turn yellow or rust colored and then fall to the ground. These are the oldest needles; new ones will develop next spring.
• Store your favorite geraniums in pots over the winter. Place them next to a basement window or under fluorescent lights. Water often enough so they don’t shrink. You can also try storing them bare root in paper bags in a cool basement, but you’ll need to prune and repot them in spring so they’re ready to go outside once the threat of frost has passed.
• Pumpkins are almost frost tolerant and must be harvested or protected when frost is forecast. Leave a few inches of the stalk when picking pumpkins. Wipe them clean with a damp, slightly soapy cloth, and then place them in a warm, sunny spot for a week or two to harden. Store them in a cool, dark place.
• The best time to plant garlic in Minnesota is within 1-2 weeks of the first deadly frost. In Minnesota, the hardneck variety of garlic is most commonly grown. Separate individual carnations a day or two before planting. Plant them, tip up with the base of the carnation 2-3 inches from the soil surface, 6 inches apart, in double rows. Cover the area with 3-4 inches of chopped leaves or straw mulch, then remove in spring after the threat of a hard freeze has passed.

Your gardening questions can be answered by calling the new Master Gardener Help Line at 218-824-1068 and leaving a message. A master gardener will call you back. Or email me at [email protected] and I will reply you in the column if space allows.

University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. The information in this column is based on university research.