Dial-a-Garden Message

for the Week of Monday, July 13, 2009

Susan Rose, Horticulture Education Specialist
Colorado State University Extension Tri River Area

Thank you for calling Dial-a-Garden. This message was recorded on Tuesday, July 14, 2009.

The evapotranspiration rate for the last seven days is 1.7 inches, which is not unusual for July. In many areas, there has not been significant levels of precipitation, so our lawns need water. Two applications a week are needed; if the water runs off before you’ve applied the 0.85 inches, break it into two or three cycles.

It is best to avoid aerating the lawn during very hot weather. This essential step in lawn care, which opens up the soil for air and water penetration, is best done in the spring and/or fall. Plan ahead before aerating and get an adequate supply of a fine compost to rake into the aeration holes, holding them open and improving the soil.

We are seeing many examples of stress responses on trees and other plants right now. Spider mites on willows, black pine leaf scale on pines, and leaf scorch on aspens and maples are all indicators of stress. It is important to water well in this weather, but roots must not be kept soggy or they will effectively shut down. It is also important to understand where the roots are; they may extend outward several times the height of the tree and water is needed over this entire area. See the Extension fact sheet on healthy roots and healthy trees at www.ext.colostate.edu/pubs/garden/02926.html for more details.

Trees aren’t the only plants experiencing stress right now; many lawns are also suffering. Overwatering or overfertilizing lawns at this time will make them even more susceptible to disease problems. Reduce stress by syringing with a short application of water in the heat of the day, to cool everything off. This should not replace the normal watering schedule. If you do fertilize at this time, make it a light application, no more than one half pound of nitrogen per thousand square feet. Don’t do this if you have trees in the lawn as we don’t want to stimulate them now. You can make up the difference later, when you make a late-season application of nitrogen in October or November after the trees have gone dormant.

Blossom-end rot on tomatoes is a common problem in hot weather. Even moisture is the solution. Tomatoes do not need a great deal of water, but they do need fairly even moisture in the soil to prevent this common situation from developing. Mulching will help keep the soil from drying out. If your tomatoes are in pots, provide some shade for the hottest part of the day and keep an eye on the moisture; you may need to water daily or even twice daily. Peppers also get blossom-end rot, though it frequently occurs on the side of the fruits. See our website at www.westernslopevegetables.org for photos and additional information.

If ragged holes are showing up in soft leaves such as squash or cucumber, the problem could be snails or slugs. Check in the cool of the evening or very early morning to find them feeding. Baits are available for control; visit www.ext.colostate.edu/pubs/insect/05515.html for more information on controlling these pests.
If you visit the Mesa County fair, July 21 through 26, be sure to take a walk through The Gardens and Arboretum. The Arboretum is located on the south side of the parking lot and covers around 51,000 square feet, showcasing many unusual trees, shrubs, and herbaceous plants. A narrow strip along the eastern end of the parking lot has over 30 different turf grasses. Around our office at the west end of the parking lot, you’ll find a number of other beds including ornamental grasses, rose gardens, a hummingbird and butterfly garden, and our magnificent cactus garden. Our newest project is the Ute Ethno-Botany Learning Garden, two and one half acres behind our building to the west, which is still under construction; this garden features plants used by the Utes and is arranged in beds representing different zones and altitudes. To the south of the building, you’ll find our adaptive garden with a variety of raised beds and containers, and beyond that is our 5,000 square foot research bed, which currently features a variety of herbs and lavender trials. We hope you will take the time to enjoy The Gardens while you are visiting the fairgrounds.

Call a Master Gardener with your yard and garden questions; we’ll do our best to help. You can reach us in Mesa County at 244-1836, in Delta County at 874-2195, and in Montrose and Ouray Counties at 249-3935.

Thank you for calling Dial-a-Garden. This message will be updated next week; have a great week!

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