Slime Mold, St. Augustine Lawngrass

Seeding A Florida Lawn, Slime Mold & Citrus Greening

University of Florida/IFAS Extension Director for Nassau County, Rebecca Jordi, answers questions about landscaping and gardening in northeast Florida.

QUESTION: What is this gray, dusty looking stuff on my lawngrass? CA

JORDI: It has been some years since I have seen slime mold on St. Augustinegrass but it can occur if the weather conditions are perfect. You can use the spray nozzle from the water hose to rinse it off, but it will disappear soon enough when things completely dry out. It is really no cause for concern and does not require any chemical treatment. Here is a pathology report from the University of Florida on slime mold in St. Augustinegrass.

QUESTION: I bought some zoysiagrass seeds and planted them this year but they have not come up. What am I doing wrong? JH

JORDI: Growing lawngrass from seed can be difficult for any of the warm season grasses and zoysiagrass is no exception. In addition, it is important to read the label on the grass seed bag to ensure you have no other pesky grass seeds which may become weeds in our area such as annual bluegrass or perennial rye.

Zoysiagrass is more difficult to establish by seed for several reasons:

1. The seed requires light to germinate so it cannot be covered with soil which is recommended for other grass seeds. If it is not covered, it becomes a tempting snack for birds and other critters. UF/IFAS recommends using some type of erosion cloth which will allow light in but keep the seed from blowing away or being devoured.
2. April through July is the best time of year to sow seed so you are right on target doing it now.
3. It generally takes about 2-3 weeks for the seeds to germinate then another 6-8 weeds to become established – maybe longer. During the germination and establishment stages, it is critical to receive sufficient water. Too much water and the seeds will wash away or pool in one area.
4. The soil must be kept moist but not wet. So, you will need to water lightly and frequently and continue to do so until the whole area has grown in. It takes a lot of patience. The biggest problem will be weeds taking the opportunity to germinate at the same time. You cannot put out a pre-emergent to control the weeds as this could kill the grass seed too.
5. The area does need full sun and the soil should be slightly acidic for best results. For so much of our area, the landscape soils can be very alkaline and this may be another reason the seeds may not have germinated well.

One other note, we cannot grow fescue here in Florida. We can grow Bermuda, St. Augustine, Bahia, centipede and Zoysia. Only Bermuda and St. Augustine can tolerate higher pH soils but the others really prefer acidic soil. Here is the University of Florida publication on zoysiagrass.

?QUESTION: What is growing on my citrus trees? JM

Citrus Psyllids New Growth
Citrus Psyllids New Growth
JORDI: I am glad you brought this in for me to identify it. This is the Asian citrus psyllid. We know it has been here in Nassau County for some time. Since it is late spring the insect will be reproducing on new growth in large numbers.

Citrus Greening

Just as a reminder – this is the vector insect which can transmit Citrus Greening. Now, don’t panic, just because the insect is present does not automatically indicate you have greening. But, if left unchecked, the insect can transmit Citrus Greening.

As you already know, this disease is devastating to the whole citrus industry and as homeowners we are no exception. The insect should be immediately sprayed with insecticidal soap. Please apply ready to use (RTU) products and do not make your own concoction from internet recipes. We do not recommend using dish soap as it can cause damage to the already vulnerable leaves. The best time to apply the insecticidal soap is before 10am or after 6pm – never in the heat of the day.

Asian citrus psyllids will be found on new growth only and they will continue to attack citrus throughout the growing season. Check all new growth on citrus trees daily for these serious pests.

Do not apply malathion or Sevin as these will kill our critical pollinators. The insecticidal soaps really work best. If you don’t see the insect, then there is no need to spray. If you do not know whether you have the insect, bring me a clipping of the new growth in a double zipped bag and I will identify for you. We have a letter box in the door at our office so the clippings can be dropped off at any time for your convenience.

Rebecca Jordi
Rebecca L. Jordi
Nassau County Extension Director
UF/IFAS Environmental Horticulture
543350 U.S. Highway #1
Callahan, FL 32011