Jan 25

Written by: bugmaster
1/25/2010 11:14 AM 

Freeze Damaged Landscape Plants:

The affects of this months historic cold weather period on our landscapes is becoming more evident every day. Some affects are seen immediately and others will keep showing up for the next several weeks to months The severity varies greatly from location to location, even among neighbors, the damage can vary. Cold air will follow paths and settle in areas within the same property. Damage can be severe on one side of a house and not as bad on another. Plants under the canopies of trees may not show damage like those in the open. Basically if you are seeing any change in your plant material, it is probably due to the cold weather.

Lawns:

Bahia grass lawns are all completely brown; they will recover in the spring. Do not water Bahia grass this time of year. Bahia needs very little water even in the summer and it is completely dormant now.

St. Augustine lawns have varying degrees of cold damage. All have virtually ceased growth meaning little irrigation is needed. What is showing in St. Augustine lawns are the patches of crabgrass, (or other weeds) they turned brown and stand out in the lawns that are still green. The crabgrass roots were not killed though and these patches will come back during the spring and summer. Since we have no registered herbicides to control crabgrass in St. Augustine, these brown patches are a good indicator of how much contamination is present in your yard. Our recommendation has always been to RoundUp and replace these areas before they spread even more, now may be the time to take stock of the problem and consider replacing these areas. You cannot RoundUp them now as you need green tissue to take up RoundUp, as temperatures warm you can mark them with turf paint for removal. Since most sod farms suffered severe damage, I would wait until spring to replace these areas. Check with your sod supplier or landscaper for the current condition of the sod they purchase.

Bermuda and Zoysia grass lawns again vary greatly. Those with some protection will show degrees of browning while others will be completely brown. Most golf courses are completely brown except over seeded greens. These grasses naturally go dormant in the winter.

Mow all lawns only as needed. Keep or increase the mowing height. Plants produce food only in the leaves and they need every bit of leaf area to recover.

Shrubs:

The more tropical species were damaged the most, depending on location. If the leaves are brown and hanging on, that indicates stem death and eventually those plants will have to be cut back to live wood. If the leaves are dropping, that is a good sign, and new leaves will probably push out. Ixora, Hibiscus, Crotons, and Golden Dew Drop are starting to drop leaves. Whatever the amount of damage, do not prune the damaged parts off or severely cut back these plants. The damaged areas help protect against further freezes and new growth appearing after a cut back is highly susceptible to another freeze. Most shrubs will come back during the spring. It may be months before damage can be accurately determined and cold damage can adversely affect plants months and years after the freeze. Cracks caused by freezing temperatures in stems and trunks can disrupt food and water transport and provide an entrance for disease organisms.

Palms:

The most affected species are Coconut, Foxtails, Christmas and Arecas. Palms grow from a center bud protected deep inside the crown (provided they were not over trimmed). The extent of damage cannot be determined for months, unless the crown or bud area collapses or falls over, do not assume the palm is dead. Decay in the form of bud rot disease often will attack some freeze damaged palms. Drenching with a fungicide can help protect the bud. New leaves that emerge after a freeze may be deformed from cold damage, this is normal and subsequent leaves should have a normal appearance. Do not trim off the brown fronds until the threat of further freezes has passed, the help protect that center bud.

Tags: