My guara's leaves are turning red on the edges and dying starting at the bottom undersid of the plant. Causes?
Depending on the variety that you are growing, I believe this is a normal color pattern for the leaves on your plant.
Check the plant for any signs of pests or spots or marks on the leaves.
If this is a new planting, make sure your are adequately watering. Once established they are generally quite drought tolerant.
A new planting needs time to send the tap root deep into the soil.
Here is a link to refresh you on the care requirements.
https://www.gardeningknowhow.com/ornamental/flowers/gaura/growing-gaura-plants.htm
Is gaura frost or freeze resistant?
Gaura is hardy in zones 5-10.
Zone 5 is temperatures to -20 degrees F.
https://www.gardeningknowhow.com/ornamental/flowers/gaura/growing-gaura-plants.htm
All of my the Gaura I have planted in my perennial beds, regardless of location have crinkled up leaves, stunted growth and now, some leaves are turning brown. I live in Westhampton beach long island and the spring has been very wet. any ideas?
In times of intense heat, many plants will go semi-dormant, allowing their leaves to roll or fold up, to conserve moisture. Try trimming back all that excess foliage and dried leaves, and let the green leaves on the basal area keep things going.
There are several pests and diseases that attack gaura. Aphids, leaf miners, spider mites and whiteflies are the most prevalent pests. Of these insect pests, aphids occur the most frequently and can often be observed feeding on the growing tips of the newest shoots.
The primary diseases which infect whirling butterflies are Botrytis, Phytopthora, Pythium and Rhizoctonia. Other diseases growers may observe on occasion are downy mildew, powdery mildew and rust. Under cool growing conditions, dark-colored purple spots may develop on the foliage. This spotting is a physiological response (not disease related) and will lessen and disappear with warmer temperatures.
https://www.gardeningknowhow.com/ornamental/flowers/gaura/growing-gaura-plants.htm
Is it ok to divide well established guara?
Guara should be divided in the spring, just as the new growth is starting.
https://www.gardeningknowhow.com/ornamental/flowers/gaura/growing-gaura-plants.htm
Should I cut them back in the winter? I live in the north east.
It isn't completely necessary, however they flower on new growth, so it will not hurt them to do so either. You can prune back in fall, or winter when they go dormant.
Here is an article for more information on these plants: https://www.gardeningknowhow.com/ornamental/flowers/gaura/growing-gaura-plants.htm
Do you cut these plants off at the end of the season or leave them on over winter?
Many people find that it tends to grow better the next season when it gets cut back. It will be fine to leave it, but for the best results it is safe to cut it back.
Here is an article that will help: https://www.gardeningknowhow.com/ornamental/flowers/gaura/growing-gaura-plants.htm
Do I need to cut gaura to ground level in the autumn?
Many people prefer this way of pruning. This will make the plant grow back more full. Here is an article that will give you some more information: https://www.gardeningknowhow.com/ornamental/flowers/gaura/growing-gaura-plants.htm