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The variety and intensity of fall colors depend on the weather. Watch the temperature before and during the time leaf chlorophyll is dwindling. Days that are warm and sunny, along with nights that are cool and crisp, but not freezing, will create the most brilliant color display. The leaf produces a lot of sugars on warm days and the leaf veins slowly close during cool nights. The closing keeps the sugars from moving out. Sugar and sunlight produce anthocyanins, which turn leaves red and purple. Carotenoids are always in leaves and yellows and golds remain fairly constant from year to year.

Soil moisture also affects tree color. Early showings of color can be caused by cool, wet summers. The reds may not be as brilliant when autumn has lots of warm, cloudy, rainy weather. The leaves make less sugar in the reduced sunlight. This is because the sugar moves out of the leaves during warm nights and the leaves have less of it to form anthocyanins and turn red and purple. A mild drought can brighten the display, but severe drought may make colors duller. Sometimes, the leaves die early from a lack of water.

Leaves may not have as much pizzazz if pests, disease and environmental problems have damaged them.

Which trees should be planted for color in my own backyard?

Maples offer the most intense fall color! For red leaf color, ask someone at your nursery about the cultivar Autumn Blaze (Acer + fremanii). This colorful and fast-growing tree combines the best traits of its parents--silver and red maple. The sugar maple (Acer saccharum), also known as the Wisconsin State Tree, grows slower than the red maple but is desirable for its symmetrical form. It turns anywhere from yellowish-orange to bright red. The cultivar Legacy shows off brilliant fall color. The amur maple (Acer ginnala) is an ornamental tree ideal for smaller spaces. It has dainty leaves and exhibits colorful red fruit in summer. Fall color is orange-crimson to deep purple. Look for the varieties Embers and Flame. The silver maple (Acer saccharinum) is the fastest growing maple and is very good shade tree. The cultivar Silver Queen is gold in autumn.

Among the oak trees, red oak (Quercus rubra) is an excellent choice for a yard, given its strong wood and glossy leaves that turn burgundy in autumn.

Pin oak (Quercus palustris) is one of the fastest-growing oak trees. This tall, symmetrical tree with pyramidal form displays reddish-brown leaves in the fall. Though the pin oak and red oak varieties offer rich fall color, they are also susceptible to Oak Wilt. Oak wilt is a fungal disease that is spread by beetles and affects the tree’s vascular system. Pruning oak trees in February and March and avoiding pruning in the summer months will help prevent this deadly disease from spreading.

In the white ash family (Fraxinus americana) Autumn Blaze and Autumn Purple are cultivars that were selected for their deep green leaves that turn reddish-purple in fall.

There are several shrubs that can add dazzling color to your landscape. Burning bush (Euonymus alata) is a large shrub with unsurpassed, bright-red foliage in the fall. Highbush cranberry (Viburnum trilobum) sports small, fiery-red berries in late summer and red foliage in autumn. Popular cultivars include Alfredo and Compactum. Dwarf summer-blooming spirea (Spiraea japonica) is covered with flat clusters of flowers and yellowish-green foliage in summer. It turns from soft pink to reddish-orange in autumn. The cultivar Goldmound is a neat, compact shrub that looks nice near buildings and in mass plantings.

Autumn is a great time to scout out nurseries in search of trees with fabulous fall foliage! This will help you landscape your yard with an array of color. Plan not only for fall color, but winter, spring and summer as well. Many of these aforementioned “all stars” will amaze you and beautify your yard all year long.

There are three remote drop off sites for samples in the county: Mannions Greenhouse and Floral in Rush City, North Branch Floral and Federated Coop (Cenex) on Highway 8 in Chisago City. There will not be a Master Gardener on site, but these businesses have agreed to hold the samples for pickup.

There will be Master Gardeners on site to answer your questions Thursday evenings from 6-8 p.m. at the Chisago County Hazardous Waste facility in North Branch.

The Lindstrom Farmers Market is now open. There is a Master Gardener there from 8 a.m.-noon every Saturday.

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Other ways to access information:

www.extension.umn.edu/county/chisago

Check out the “Hot Topics” box in the middle of the page for current Chisago County Master Gardener news and events. You can also click on “Ask a Master Gardener” next to the cute little flower on the right hand side of the page. Here you can search 1000s of answers from Master Gardeners around the state. If you don’t find your answer, you can submit a question online or search for University publications.

Bell Museum of Natural History

For information about snakes, skunks, raccoons or other wildlife around your yard, call the wildlife information line at (612) 624-1374 or www.bellmuseum.org.

Master Gardener voice mail: 651-237-3080

Leave a message and a Master Gardener will call you back within a couple of days.

Master Gardeners will be moving to the “Anderson Chiropractic” building in North Branch soon. A fixed lease for three years was approved by the County Board. Extension Services are also relocating to this site, by the Lake State Credit Union building.

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