Planning for controlled burns
By David G. Hallauer
Meadowlark Extension District Agent
As I look out the window today, the only snow left is in road ditches and piles at the end of parking lots. Twenty four hours from now is anyone’s guess! Either way, the calendar says that spring is approaching. For many grass producers, that means a prescribed burn.
Prescribed burns are a regular way of life for Flint Hills producers. Warm-season grasses like Big Bluestem and Indiangrass respond well to fire, as do the animals that graze them.
For cool-season grass producers, it’s a different story. Brome and fescue simply don’t respond the same way that warm season grasses do. In fact, regularly burning cool season stands can actually hurt stands. Burning of cool season stands may also not occur late enough to control woody species that leaf out later in the spring, further reducing the burn’s desired effectiveness.
Controlled burns no doubt have their place, but they need to be evaluated and carefully planned. Start by determining the desired outcome for the burn. If weed and brush control is your focus, determine whether you have a sufficient fuel load to carry a fire that will do a good job of control—and if the species you desire to control will actually be controlled with the timing of the fire. Most fuel loads won’t support the presence of much green grass, meaning warm-season stands are often burned in mid-April and May, cool-season stands in March.
Second, determine if you are prepared to conduct the burn safely. No prescribed burn should occur without advance planning and permission from the appropriate local authorities. It doesn’t take much of a wind shift or change in fuel load to completely change the size of the fire and its direction of travel. Make sure that adequate planning and help is lined up to conduct the burn safely. If you have any reservations—err on the side of caution and plan for another day.
For information on planning and safety when conducting a prescribed burn, check out our K-State Research & Extension controlled burn publications available through your District Extension Office and in many cases local Natural Resources Conservation Service offices. For regulations, check with local authorities to make sure you are following local guidelines appropriately.
Iris leaf spot
If you’ve had iris leaf spot before, early March is the time to get a head start on control for the coming year.
Start by removing old, dead leaves that can harbor the disease from year to year. Iris leaf spot is a fungal disease that attacks the leaves, flower stalks and buds of iris, particularly during wet periods in the spring. Emerging leaves eventually show small (1/8- to 1/4-inch diameter) spots with reddish borders. Surrounding tissue first appears water-soaked, and then yellows. Spots enlarge after flowering and may coalesce, maybe even killing individual leaves. Though the disease will not kill the plant directly, repeated attacks can reduce plant vigor so that the iris may die from other stresses. Spores are passed to nearby plants by wind or splashing water.
Removal and destruction of old leaves may well be all that is needed if plants were only lightly infected. Heavier infections should be sprayed with an appropriate fungicide starting when leaves appear in the spring. Repeat sprays every seven to 10 days for four to six sprays. Iris leaves are waxy, so be sure to include a spreader-sticker in your spray to ensure good coverage.