Extension News

Dr. Grow-It-All Offers Fall Gardening Tips

Note to media editors: This is the Garden Column for the week of Sept. 14, 2007.


It’s hard to believe that fall has almost arrived. Gardeners can do many things to prepare for next year’s lawn and garden. Here are just a few tips from Dr. Grow It All.

Planting and Keeping Tulip Bulbs
Several cultural practices can help prolong the life of tulip bulbs. Make sure to select the largest bulbs possible. Except for the species tulips, top quality bulbs are 12 centimeters or more in circumference. The larger the bulb, the longer the life of the bulb. In selecting bulbs, also look to make sure there are no soft spots, blemishes or fungus growing on the bulbs. Tulips perform best in full sun and well-drained soils.

Tulips should receive at least 6 to 8 hours of sun. Tulip bulbs decline rapidly in shady locations. The bulbs often rot in wet, poorly drained locations. Plant the bulbs 6 to 8 inches deep. Planting depth is measured from the top of the bulb to the soil surface. After planting tulip bulbs, make sure to water them. This enables the bulbs to develop a good root system before winter arrives. October is an excellent time to plant tulips. However, tulips can be planted as late as December if the weather permits.
Controlling Creeping Charlie
This is the best time of year to rid your lawn of this invasive ground ivy. Apply a broadleaf herbicide product containing 2,4-D or triclopyr to ground ivy infested areas. 2,4-D is an active ingredient in many broadleaf herbicide products. Triclopyr can be found in Ortho Weed-B-Gon Chickweed, Clover, and Oxalis Killer for Lawns and a few other products. Herbicide applications should be made between mid-September and Nov. 1.Two applications are most effective. The second application should be made 28 days after the first.

Storing Cannas and Dahlias
Cannas are the easier of the two to overwinter. The most critical factor in the success or failure of storing canna rhizomes is moisture. If they are packed while still moist or wet to the touch, they will rot. Therefore it is best to lift the rhizomes and place in a well-ventilated location to dry for a couple days. Then find a paper sack, box or bucket and place the clumps inside. Store the cannas in a cool (40 to 50 F), dark location and keep them there until danger of frost has passed in the spring.  Check the containers periodically to ensure rot has not started.

Dahlias need a little more attention. After a killing frost has destroyed the above ground foliage, remove the above ground parts and leave the tuberous roots sit in the ground for 1 to 2 weeks. This gives the roots a chance to cure before their removal from the soil. If the cultivar name is important, write the name of each plant on a tag or label before digging the dahlias. They all look similar after being dug.

Using a spade or potato fork, carefully lift each clump out of the ground and immediately attach its identification tag to one of the tubers. Next, wash off as much of the soil as possible. Allow the tubers to dry to the touch (usually one or two days), and then cut the stems back to the crown.  Place the tubers upside down and cover with vermiculite, peat moss, wood shavings or sand and store in a cool and dark location.


Contacts :

James Romer, Horticulture, (515) 294-2336, jromer@iastate.edu

Jean McGuire, Extension Communications and Marketing, (515) 294-7033, jmcguire@iastate.edu