Drought Stress - Master Gardeners Frederick County, Maryland
Drought StressThis spring (1999) is the third consecutive Trees can obtain water longer duringseason that Frederick County has drought conditions than shallower rootedexperienced a drought. Most people are not shrubs and flowers. To simplify thingsaware of how dry things are because the remember that lawns require the most waternight time temperatures are comfortably in a landscape. Annual and perennialcool during spring and fall. I am very flowers planted in full sun are next, shrubssurprised to be writing about drought once follow, and trees are the least needy.again, but it is very dry and the time to water Drought injury in trees will start in theis now. uppermost branches first and work its way down if drought conditions persist. In treesProlonged drought stress predisposes plants especially, symptoms will not appear for 6to pest problems. A plant under drought to 9 months after the drought wasstress is in a weakened state and its defenses experienced.are low. Insects and diseases take advantageof the situation and add to the plants stress. When temperatures soar and natural rainfallThe result is often observed the following diminishes begin to observe your landscapeseason with pest damage that seemed to often or daily for drought stress. Find a plantappear overnight when in reality the to use as an indicator. Lawn areas in the sunproblem started the previous season during next to walks and driveways show signs ofor following the drought. The solution is to heat stress early. Certain annual flowersavoid prolonged drought conditions through planted in full sun (inpatients, begonias) arewatering. also good indicators of drought. When the indicator plants show signs of drought applyIdentifying drought conditions is not always water to relieve them and pay attention toeasy. Outward signs on deep rooted plants the results. Indicator plants require watertypically are not obvious. Many variables more frequently than the rest of theplay a part in reaching drought conditions. landscape. Plan on watering the entire landscape within a few days.These include: • lack of natural rainfall The following tips will help conserve water • soil type as you irrigate to avoid drought stress: • air temperature & humidity • wind conditions Mow lawns higher during the hot summer • sun exposure months, a height of 2½ - 3" is best. • plant type Control weeds, they compete with the desirable plants for water. EQUAL ACCESS PROGRAMS EQUAL OPPORTUNITY EMPLOYER
Maintain 2 - 3" of mulch in flower beds toreduce evaporation; cool soil; and controlweeds.Water infrequently, slowly and deeper.Frequent light watering encourages shallowroot growth and weeds. Water for a longerduration less often.Water in the morning, before 11:00 a.m..As much as 40% of the irrigation water canbe lost to evaporation during the heat of theday. Watering in the late day and nightpromotes fungal diseases.Direct water to the plants. Avoidoverspraying sidewalks, driveways andstreets.Repair leaks. Leaking hoses and irrigationpipes waste water by not applying it to theneeded area.Through identifying drought stress andobserving the results of watering you willget a "feel" for the particular needs of yourlandscape. The constant observation can alsoalert you to developing pest problems beforethey become very damaging. When the hightemperatures and lack of rainfall persist formore than a week, you will see droughtstress if you look for it.For more information about horticulture orthe Master Gardener Program in FrederickCounty, call the Frederick County Office ofthe Maryland Cooperative Extension,301- 600-1596, or visithttp://www.frederick.umd.edu/. Ourmission is to educate Maryland residentsabout safe, effective and sustainablehorticultural practices that build healthygardens, landscapes and communities.