The two biggest problems homeowners encounter in the fall are Brown Patch and the emergence of cool season weeds.
Rhizoctonia solani, or Brown patch appears as circular or irregular shaped patches of light brown thinned grass. The grass is yellowish and may have a smoke ring on the outside edge. The grass in the center of the ring may recover, leaving a ring effect. Brown Patch can spread rapidly and can be up to several yards in diameter. The leaves become rotted and can be removed from the runner with only a slight pull. The fungus attacks the base of the leaf creating a water soaked dark grass blade that soon wilts and turns brown. Unlike Take All Patch, Brown Patch usually is not fatal.
Brown Patch thrives when nighttime temperatures are between 60-70 degrees and when daytime temperatures do not exceed 85. BROWN PATCH WILL NOT GROW IN THE HEAT OF THE SUMMER. In September, we can see the onset of Brown Patch if we get a little cool front blow in. However, if daytime temperatures rise and stay consistently above 90 degrees the spread of the disease will cease. Another contributing factor to the spread of the disease is prolonged leaf wetness. Usually we see heavy rain events in front of those approaching cool fronts creating ideal conditions for the spread of Brown Patch.
Cultural conditions that contribute to the spread of Brown Patch are over fertilization, overwatering, poor air circulation, bad soil aeration, poor drainage, excessive thatch, or too much shade.
We often get customers that tell us that the Brown Patch will reappear in the same spots every year. By improving some of cultural conditions many times you will see these reoccurrences stop. Improve drainage, reduce irrigation, thin out some trees and make sure you are using the proper fertilizers such as the Nitro Phos or Microlife products. DO NOT USE FERTILIZERS HIGH IN NITROGEN CONTENT IN THE FALL!
If you get Brown Patch in the same spots every year, it is advisable to pre-treat those areas just before the first cool front. Almost all the fungicides on the market with Brown Patch on the label, work well as a preventative but not as well as a curative.
Fall and Winter Weeds
Once the daytime temperatures remain below 90 degrees it is safe to use most broad leaf weed killers again without the stress that they sometimes put on St. Augustine and Bermuda lawns. Always use caution with these products as they can kill all broad leaf plants they come in contact with. Flowers are broad leaf plants and these products do not know the difference between weeds and flowers.
All those weeds that you saw last winter will be back because before they died from the heat they spread some of their descendants in the wind. Even those weeds that you killed with a weed killer in the spring went to seed before they died. So if you want to break that cycle of winter weeds popping up every year another course of action needs to be taken.
Most of our customers have found a better approach to control weeds is the use of pre-emergent weed killers such as Nitro Phos Barricade. These products work by killing plants in the first stages of germination. I said plants instead of grass because they will kill ALL plants in the early stages of germination. The chemical has no way of distinguishing between a weed and a leaf marigold or whatever flower or vegetable seed you may have planted. So be careful not to introduce these products into any area where seeds have been planted and have not yet germinated.
For an organic approach to pre-emergent weed control you can use corn gluten meal in a powder form.
Things to do in September
Not a whole lot to do in September because it is still plenty hot and too early to plant much of anything. Listed below are a few things you can be doing this month in your lawn and garden.
*In September the nighttime temperatures start cooling which will start promoting new plant growth. Light pruning on most plants followed by fertilization will get some healthy new growth and flowers for the fall.
*Prune roses not more than one third and fertilize.
*Prune your flowering perennials lightly and fertilize to get a good show in the fall.
*It won’t be time to start fertilizing the lawn again until later in the month. DO NOT USE A FERTILIZER WITH A HIGH NITROGEN CONTENT as it promotes Brown Patch. Use Nitro Phos Fall Special lawn fertilizer or Microlife 6-2-4 organic fertilizer. Both are formulated to give you just the right amount of nitrogen.
*Get a jump start on brown patch in your lawn. Apply Nitro Phos Eagle Fungicide to areas where you have had brown patch in the past.
*Many cool season bedding plants will start showing up in the big box stores. DO NOT BUY PANSIES until the end of October or the first of November.
*Our homegrown snapdragons and pansies should become available in the last week of October or the first week of November.
*Grub damage may start showing again as the grubs start maturing. Grub control must be done in July when the grubs are immature. The treatments available today do not work well, if at all on mature grubs.
For great gardening products and information, come by the Growers Outlet and visit with any member of our team to get the help you need or go to our website at www.growersoutletinwillis.com. We have the products and knowledge to help you have the prettiest yard on the block.