Leaf Spot

 

                                           one yard uses preemergent products one does not

     white seedheads of Poa show where the groundskeeper applied preemergent

                                         Can tell where preemergent was applied - White seed head of weed

Horticulture Hotline 02/19/24

By Bill Lamson-Scribner

 

It is time to get your preemergent products out before your summer annual weeds start to germinate. Prevention, being pro-active, and protection is the best way to deal with summer annual weeds. Where you have used a preemergent product and where you have not, is usually obvious if your timing was good.

 

Indian Hawthorn, Raphs or Raphiolepis have been really suffering. Raphs have been plagued with leaf spot for years. It seems like right after the Red Tips (Photinia) were virtually wiped out by Entomosporium leaf spot, the diseased began attacking the Indian Hawthorn.  Indian Hawthorn and Red Tips are in the same plant family as roses (Rosaceae). 

 

When dealing with any plant that is very susceptible to a leaf spot disease (ligustrum a big issue now, roses, Loropetalum) I like to think of several different factors:

1.      Is this plant worth keeping in the landscape or should I replace it with another plant that is not susceptible to disease.

2.      Is this plant worth spraying ever 14 – 28 days to keep it in my landscape?  To keep an Indian Hawthorn alive, it needs a life-support system.  The plant must be sprayed at least monthly or it will get leaf spot again. You would want to start spraying anytime and right now as new leaves are forming is the best time to start spraying.

3.      What cultural practices can I do to help relieve the pressure of the disease?  The removal of fallen foliage (sanitation) is key when dealing with a leaf spot disease.  Having a healthy soil, as determined by a soil test, is also very important because a stressed plant is more susceptible to disease.  Providing the correct amount of water preferably through a drip system, so the plants are not over-watered, or drought stressed. Overhead irrigation could spread the disease. Proper fertility as determined by the soil test is also important.  Use nitrogen fertilizer very sparingly in small amounts because flushes of new growth are more susceptible to leaf spot.  Choose “resistant” varieties such as “Olivia”.    This does not mean that this plant will never get this disease; it is just more resistant to the disease. Mulch like Cotton Burr Compost will help prevent splashes of water drops that could spread the disease.  Also, this mulch will lower the watering needs of the plants. Bioscience products like KeyPlex should be considered. KeyPlex will thicken the cuticle of the leaf making more resistant to the disease as well as more drought resistant. Pruning for good air movement.

4.      What control products will work best on this disease?  If you decide to spray, be prepared to spray often.  Honor Guard, Banner, Dithane (Mancozeb), and Kocide are good choices. These products should be used in rotation and according to label. When spraying these control products, an appropriate surfactant should be used if the label recommends one.

 

I am in yards all the time and leaf spot diseases are the most common disease I see in our Lowcountry landscape. I usually recommend replanting the area with plants that are not susceptible to disease; however, that can always change. I can understand spraying roses all the time with all the flowers they produce. Indian Hawthorn, one flush of flowers – ah, not so much.

 

Always read, understand, and follow product label. The product label is a Federal Law.

 

Last Minute Check List

 

Horticulture Hotline 02/15/24

By Bill Lamson-Scribner

 

The Tulip Magnolia (Saucer Magnolia) is blooming in the Lowcountry.  It is time to be sure the winter projects have been completed, and the proactive spring projects in the yard and around the house are in the works.

 

Trees grow. Some experts say around 18 to 24 inches at the tips of the branches all around the circumference of a healthy tree. Areas of grass might be shaded and thin that were once high-quality turf. Now, might be a good time to cut new bed lines and let the tree have more room to grow. Check the sides of your house for limbs rubbing the paint off your house. The paint protects your house like your skin protects you or like bark protects a tree.

 

Look above your roof line and see if any limbs are growing above your roof that could allow varmints (squirrels, raccoons, or the loveable possum) into your attic. Make sure your source of power to your house is free of limbs. Hire an insured arborist if you need some pruning done. Before a tree puts on new leaves, is a great time for an arborist to inspect the health of your trees.

 

Any transplanting or planting of new trees or shrubs should be done as soon as you can. Try to get them in the ground before the plant flushes out new growth or blooms. If you are buying a blooming plant that you want a specific color or to match a color you already have, you may have to wait to see that the bloom on the plant (do not always trust the tags) is the color you want; otherwise, the sooner you can plant the better.

 

When planting remember the Diehard Transplant or GroTabs, it is like yogurt (full of probiotics). Diehard Transplant adds all the good bacteria, wetting agents, and fungi into the soil that a plant needs to help with survival. Remember the old saying when planting, “plant it high and it will not die!”

 

Intice 10 perimeter bait is a great product to put out around the perimeter of your house for roaches, crickets, sowbugs, earwigs, silverfish, millipedes, and certain ants. Intice 10 is a LEED tier 3 product and N.O.P. (National Organics Program) compliant, so it is considered very safe.

 

Intice 10 should also be broadcasted in the yard for mole crickets. Mole crickets come to the surface on these warm days and love to eat this bait!

 

Get out your preemergent, or forever fight weeds!! Remember to treat you turf and beds, so you do not have to waste time battling the weeds. I usually wait until my bald cypress starts to “needle out” and then I go on an organic binge with SeaHume, Cotton Burr Compost, worm castings and others; however, this year I am already seeing new growth on some plants, so I guess it is time for the organics. Of course, anytime is a great time for organics.

 

If you have a history with fungus or insects on certain plants, sanitation, lime / sulfur, and your fungicide or insecticide of choice is good to put out now to protect the new growth. With these cloudy, overcast days brown patch / large patch has been flourishing in lawns.

 

Other things – make sure mower is good to go – air filter is key, check irrigation, treat for fleas (growth regulator is key) and ticks, take soil test, prune roses, work on breeding sights for mosquitoes, kill winter weeds before they make seeds for next year, spray neem oil or horticultural oils for overwintering insects, apply Dominion Drench to perennial insect loving plants…

 

Spring in the Lowcountry… Work hard, then head to an oyster roast!

 

Always read, understand, and follow product label. The product label is a Federal Law.

 

Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations 481 Long Point Rd in Mt. Pleasant (971-9601), 3325 Business Circle in North Charleston (760-2600), or 606 Dupont Rd, in Charleston (766-1511). Bring your questions to a Possum’s location, or visit us at possumsupply.com. You can also call in your questions to “The Garden Clinic”, Saturdays from 10:00 AM to 11:00 AM, or listen to the replay of Saturday’s show, Sundays from 11:00 to noon on 1250 WTMA  (The Big Talker). The Horticulture Hotline is available 24 / 7 at possumsupply.com. 

Gardeners Start Your Engines!

 

Horticulture Hotline 02/06/2024

By Bill Lamson-Scribner

 

The Saucer or Tulip Magnolias are blooming, which usually indicates spring is rapidly approaching. Camellias are blooming. My Bottlebrush have survived so far. Hibiscus, lantana, and cassia not so lucky. Since I was talking about the first Lamson-Scribner on “The Garden Clinic” last Saturday, I figured I would include a picture of him saving Bordeaux’s grape / wine industry with Bordeaux Mix – a fungicide he helped developed.

 

The time is now to introduce some organics to your landscape. SeaHume, with its high humic acid, seaweed, and carbon content, is a great choice. SeaHume is very concentrated organic material that has been compacted under heat and pressure over time, and is mined. Cotton Burr Compost also does a terrific job this time of year. The two products together form a serious synergy in the soil. Food for microbes and a five-star hotel!

 

The soil temperature indicates that it is just about time to apply preemergent products to your beds and turf. Valentine’s Day and the running of the Daytona 500 are just around the corner. The time to apply the magical weed preventer is coming up fast.

 

Depending on which Phd doctor you believe, crabgrass germinates when the soil temperature (3 inches deep) stays above 55 degrees (some doctors say 57 degrees), for 3 straight days provided adequate moisture in the soil. Now some doctors say remains 57 degrees or above for 24 hours at a depth of 3 inches with adequate moisture.  The manufacturers of the preemergent products suggest that you apply the product 2 weeks before the temperatures are right, so you must be able to predict the future. Do you have a crystal ball? If you are not into monitoring the soil temperature and do not have ESP (do people, still use the term ESP), Valentine’s Day or the running of the Daytona 500 should work for you.  Spreading a preemergent product now could save hours of spot spraying later.

 

The turf areas as well as the landscape bed areas will greatly benefit from the use of preemerge products. Not only will the yard look better, but your plants will not have to compete with the weeds for sun, nutrients, and water. If you are controlling weeds with preemergent products, there are less weeds there for you to spray or pull, saving you time. There is also less stress on you trying to find time to control the weeds in your yard later once the weeds have emerged. Control them now with a preemergent control product!

 

For those new readers of the Horticulture Hotline, preemergent control products kill weeds as they germinate.  The weeds never come up and you never have to worry about them.  Crabgrass, goosegrass, barnyardgrass, crowfootgrass, dallisgrass (seedling), foxtail, annual bluegrass, smutgrass, barley, kikuyugrass, wild oats, bittercress, carpetweed, chickweed, Carolina geranium, henbit, knotweed, lespedeza, marestail, black medic, mustard, oxalis, pineappleweed, pigweed, redroot, parsley-piert, purslane, rocket, shephardspurse, speedwell, spurge, and woodsorrel are examples of weeds controlled by preemergent products.  Small seeded annual weeds are controlled by preemergent products.

 

Read the label of the specific product that you are using to get an exact list of weeds that the manufacturer has tested and shown to control. Preemergent products applied now do not control winter annual weeds that are already up like annual blue grass. To control annual bluegrass, you would have used a preemergent in August and again in October (this could vary with products and rates – follow the label).

 

Clover, Florida Betony, Nutsedge and Dollar weed are not controlled by preemergent control products.  These are perennial weeds. Weed Free Zone is a liquid that will do a good job on controlling many of your broadleaf weeds. The Nutsedge will require a different product and is most likely not visible right now.  It is important to control these weeds that you see now (henbit, chickweed, annual bluegrass) before they go into their reproductive stage (flowering).  A weed in its reproductive stage is harder to control than a weed in its vegetative stage. By controlling the weed now, you avoid having to deal with more weed seeds next year.

 

It is very noticeable when you ride through the Lowcountry which homeowners and which businesses used preemergent products last fall at the correct time. One business or home lawn will be nice and brown and dormant without a spec of green in sight. Right next to it will be brown turf mixed with green weeds. Again, it is very important to control those weeds that are up now before they begin to flower.

 

If you missed your fall application of preemergent, use a post-emerge product along with your preemergent product. Kill what weeds are up and control summer annuals weeds before they come up! Great way to be a lawn hero by killing the weeds and not have to mow weeds for the next two and a half months when you are basically mowing weeds. Killing weeds before they seed reduces your weed population greatly. One annual bluegrass plant produces about 6000 seeds! Some people will say do not worry about controlling winter weeds now because the heat will kill them in May. Do you want to add all the weed seeds to your yard in the mean time and have your grass coming out of dormancy compete with the weeds?

 

If you are trying to control weeds in the lawn that are up and starting to flower or seed, mow – wait 2 days and spray – then wait at least another 3 days before you mow again. The mowing will get the weeds actively growing and weeds that are actively growing are easier to kill. If the product is root absorbed, be careful around desirable plants, and water-in properly. If you water in too much, you could move the product passed the shallow root zone of the weed you are targeting.

 

Always read, understand, and follow product label. The product label is a Federal Law.

 

Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations 481 Long Point Rd in Mt. Pleasant (971-9601), 3325 Business Circle in North Charleston (760-2600), or 606 Dupont Rd, in Charleston (766-1511). Bring your questions to a Possum’s location, or visit us at possumsupply.com. You can also call in your questions to “The Garden Clinic”, Saturdays from 10:00 AM to 11:00 AM, or listen to the replay of Saturday’s show, Sundays from 11:00 to noon on 1250 WTMA  (The Big Talker). The Horticulture Hotline is available 24 / 7 at possumsupply.com.