Ask a Master Gardener: Keeping woodpeckers at bay

Dear Master Gardener: Our house has cedar siding and the woodpeckers are causing a lot of damage to the house. Is there anything we can do to deter them?...

01274-004.05 Pileated Woodpecker female pauses whle feeding on crabapples during winter. Food, survive, habitat management, backyard.
01274-004.05 Pileated Woodpecker female pauses whle feeding on crabapples during winter. Food, survive, habitat management, backyard.

Dear Master Gardener: Our house has cedar siding and the woodpeckers are causing a lot of damage to the house. Is there anything we can do to deter them?

Answer: There are nine species of woodpeckers found in Minnesota. Flickers and Yellow-bellied Sapsuckers leave for the winter, but the others stay here year-round. It is important to keep in mind that woodpeckers are a protected species and it is illegal to kill or trap one without a permit. Wood siding, especially soft wood like cedar, attracts woodpeckers who leave behind holes ranging in size from one-fourth inch to 1 inch or more. Most of the damage occurs from February through June. Woodpeckers peck for three reasons: communicating, feeding, or roosting. They often focus on the area just below the eaves. The "drumming" you hear is the woodpecker searching the house for hollow spaces. If a woodpecker is looking for food it will usually leave several small (less than ½ inch) feeding holes scattered over an area or formed into rows. One or two larger holes (an inch or more) are typically a sign of roosting or nesting behavior. It is critical to take action as soon as a woodpecker starts making holes in your siding, and before it has time to make it a part of its routine.

There are some techniques you can try to scare off your woodpeckers, but before you begin, cover or repair any existing holes. For small pea-sized holes, you may want to squirt a small amount of linseed oil in the openings to kill any insects that may be attracting the woodpeckers. Seal all openings in your siding with caulking to keep insects to a minimum. Following are some ideas from the University of Minnesota and the DNR:

• Hang bird netting from the outside of the eaves to the side of the house about 18 inches below the roof line. Bird netting can also be hung to cover the whole side of a house. Hang at least 4 inches out from the house staring at the roof line. You will need to close off the ends so that birds cannot get underneath.

• In hard hit areas attach 1-inch by 1-inch boards to the house and then place metal screening over the boards to prevent the woodpecker from reaching the house.


• You can purchase "Scare-eye balloons", which are designed to look like a large predatory bird eye. The balloons should be placed in front of the affected wall or area and should be moved or removed after about a week so that the bird does not get used to it.

• Fake owls with mechanical heads that rotate and screech have been effective as a deterrent. They should be placed 10-15 feet high in a visible spot, such as the edge of the roof or upper floor deck railing.

• Bird scare tape, also called "flash tape," is a thin shiny ribbon of Mylar. It is silver on one side and colored on the other. When properly used, the tape flashes in the sun and rattles in the breeze. The flashing and rattling frighten birds. Tack several long streamers above the affected surface about a foot apart, making sure they are able to move in the breeze.

• Attach pie tins or unusable CDs or DVDs to a string and hang them in front of the affected area. Tins should be placed so that they spin freely in the wind.

Dear Master Gardener: I would like to start some plants from seed and was thinking of building a coldframe to hold my plants until my garden is ready. Do you recommend putting in a coldframe?

Answer: With our short growing season, coldframes will help you get a head start on spring. Starting garden plants from seed is a great idea and gives you more plant choices. After your seedlings are well established, harden them off before transplanting them into the garden. Hardening off takes about seven days. If you have only a few pots, put them outside each day for increasing periods of time. If you have a large number of plants, a coldframe is indispensable as it eliminates moving the plants. A coldframe is also used to grow seedlings to a transplantable size and hold them until the garden is ready.

Building a coldframe takes a few hours and requires only simple tools such as a hammer, drill, nails or wood screws, and a saw. Beth Jarvis at the University of Minnesota Extension recommends the following procedure:

First, buy a 4-foot by 8-foot sheet of waferboard or plywood and three 8-foot lengths of 2-by-2. Cut the waferboard or plywood yourself or have the lumberyard cut it into four 2-foot by 4-foot pieces. Cut one 2-by-2 into four 2-foot long pieces. Cut the other two 8-foot 2-by-2s into four 4-foot pieces and save them for the cover.


Set the 2-foot by 4-foot pieces to form an open box with the edges of the side wall pieces flush with the edges of the front and back pieces so the box will be slightly wider than deep. Nail or screw the edges of the 2-by-4s into the 2-by-2s to reinforce and stabilize each corner. The finished product will be an open-ended box, 4 feet wide, 4 feet deep, and 2 feet high. Paint the structure inside and out with a white, oil-based paint to prevent deterioration. The white paint reflects light inside the coldframe.

Place the coldframe in a site which receives direct sun at least half the day. To let the sunlight in, lower the front by digging a trench six inches deep along the front and tapering back along the sides. Secure the coldframe by packing the soil back along the sides and front of the coldframe. (Gardeners with woodworking experience could cut the side panels at an angle and shorten the front wall, instead.)

Build a cover or use old storm windows. To build a cover, buy a clear sheet of wavy fiberglass and cut it in half so it forms two 4-foot-long pieces. (Use a power saw as a hand saw will splinter the fiberglass. If you have no power saw, the lumber yard will cut it for you.) Make the cover frame from 4-foot lengths of 2-by-2s. Set the side pieces to overlap the front and back pieces so the top will fit well. You can also use 1-by-2 lumber, but the weight of the 2-by-2s helps keep the cover from blowing off in a storm.

Buy two 8-foot pieces of fiberglass molding cut in half. Use one piece to fill in the gaps in the front and back of the lid. The other is an arched piece for each side. This frame may be painted to match the coldframe. Set the molding pieces on the frame and fit the fiberglass pieces over the molding. There will be some overlap in the middle. Drill holes for the nails to keep the fiberglass from cracking when it is nailed or screwed into place. Hinges can be used to secure the lid to the frame, but they are not necessary.

Eight standard 21-inch by 10.5-inch nursery trays of seedlings will fit in this coldframe. To keep the undersides of the trays clean, put a piece of landscape fabric in the bottom of the coldframe or make a slotted floor from lath strips spaced and nailed onto two other pieces of lath. Prop the lid open with a stick or leave the lid ajar a little more each day to harden off the plants inside. Coldframes can also be used to hold purchased plants until the garden is ready and to start fall crops of broccoli and other cool-season plants.

If you would like diagrams for building the coldframe and additional information about cloches (another temporary structure which serves as a mini-greenhouse and is set directly into the garden) the following website may be beneficial:

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Dear Master Gardener: I have heard about people starting seeds outdoors when it is still cold outside, how do I do this?

Answer: What you are referring to is winter sowing. Winter sowing has been around for several years now, and is a great way to start native plants or a lot of plants without the investment in lights, seed-starting trays and the other equipment needed to start seeds indoors.

Winter sowing in an easy germination method. During winter, seeds are sown into mini-greenhouses that you make yourself from recyclables such as gallon milk jugs, soda bottles or the clam-shell containers from takeout food. You can plant them anytime during the winter and then set them outside no matter what the weather. The theory is that the seeds know when to sprout and they will come up at the right time.

The University of Minnesota Extension recommends the following procedure:

• Clean desired tall, large, plastic recyclables such as milk jugs, take out containers or 2-liter soda bottles

• Carefully cut the container, leaving at least three inches on the bottom half for potting soil, and a small portion of the plastic intact to act as a hinge

• Cut or punch holes in the bottom of the container for drainage; discard jug cap to provide air movement and allow moisture in

• Place a minimum of three inches of clean, sterile potting soil in the container


• Water the soil, and let drain

• Sow seeds at appropriate depth according to seed packets

• Good seed options include vegetables such as lettuce, kale, radishes, and kohlrabi, or annual flowers such as alyssum, pansies, and viola, or hardy perennials that need a "chilling" period to germinate such as Echinacea, flax, and yarrow

• Lightly water seeds in

• Label your container with a plant marker on the inside or on the bottom of the container; be aware that even permanent marker will fade and may need to be reapplied

March Garden Tips

• Bring stored geraniums and tuberous begonias up from the basement by the end of the month. Pot them in fresh soil and place them right by a sunny window or under fluorescent lights. Water them regularly to initiate new growth, and fertilize them every two to three weeks so they're growing actively in time to move them outdoors once the frost danger has passed, by mid to late May.

• If your oak trees need trimming, have it done by the end of this month to help prevent the spread of oak wilt disease. Avoid pruning oaks from April through June, as the scent of freshly exposed wood attracts sap beetles that carry the fungus from one tree to another.


• Start planting tender bulbs indoors in mid to late March through early April. Cannas, dahlias, tuberous begonias and caladiums started indoors bloom earlier in the garden.

• Stay off grass while it's still frozen or muddy to avoid compacting the soil or uprooting tender grass shoots.

• Consider purchasing bare-root divisions of herbaceous and woody perennials to plant when the ground warms.

• Heavy spring snowfall often weighs down evergreen boughs and flattens newly emerging bulbs. It is probably best to just let the snow melt on its own. If you prefer to remove snow from evergreens, scoop it off gently rather than hitting the branches, which are still brittle at this time of year and prone to breakage.

• Prune apple, crabapple and other fruit trees either this month or next as long as it is before the buds break and growth begins.

• Cutback yellow and red raspberry canes to 4-5 feet tall before new growth begins. Prune off side branches of red and black raspberries to 12-18 inches and prune all but 4-5 canes to the ground.

University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension Service. All information given in this column is based on university research. To ask a question, call the Master Gardener Help Line at 218-454-GROW (4769) and leave a recorded message. A Master Gardener will return your call.

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