With all the cold temperatures we have been having lately I have been covering my citrus with an old sheet but my neighbor says that will not protect it from the cold very well and I need something heavier. Is this true?
With all the cold temperatures we have had of late it is important to protect citrus and other cold sensitive plants. Your sheet will protect your citrus form damage if temperatures go down to 29 to 30 degrees Fahrenheit. Once they dip below 29 degrees your neighbor is correct in that the thin sheet will not help protect the tree.
If you want better cold protection for your plants and still want something light weight, try using row cover to wrap the tree. Row covers can protect sensitive plants, depending on the thickness and type of cloth used, down to 24 degrees Fahrenheit. You can increase the effectiveness of lighter weight row cover by using old fashion Christmas lights in the tree in to add some heat in addition to covering the tree.
Row covers can also be used in your vegetable garden to extend your growing season. It keeps wind and pests out, allows moisture in and extends the growing season for your plants. Row covers are less expensive than constructing cold frames, can be stored away in the summer and reused the next season. They are more easily moved around your garden as the seasons change and make an easy to construct shelter for tender plants and will help harden-off seedlings that are directly seeded.
Winter crops like chard, kale, broccoli and carrots do well when they are direct seeded in early February. After you have amended and prepared your planting bed, plant your seeds and then place row cover over the soil surface and secure it. Covers can be secured with landscape staples, rocks or bricks. Or you can purchase a row cover kit. Most kits include hoops, protective film (row cover), fabric clips and staples. Since the row cover fabric breathes, seedbeds can be watered through the fabric. After germination occurs, remove the row cover or leave it nearby, depending on the weather (or pest pressure), but check regularly to adjust the fabric as needed. Once the plants are growing you will want to use hoops to help raise the fabric over the protected bed so that it is not touching the plants. Mulching with bark, straw or compost is also a good idea in the winter to conserve moisture and discourage weed growth. Thin your new seedling plants as recommended.
Row cover can also be used to protect plants from insects. A successful example of using row covers for this purpose is at the Fair Oaks Horticulture Center where the UC Master Gardeners of Sacramento wanted to protect a cherry tree from the Spotted Wing Drisophola (SWD) pest. They constructed a tent around the tree using Agribon Row Cover. They were able to demonstrate this as an effective cultural method to exclude the harmful SWD pest: no SWD was found on the crop. The cost was $200, it took a few people and ladders to construct the cover, and temperatures were monitored in the hotter months — but this shows one of many creative uses for row cover in the garden or farm.