Sunday was bitterly cold in Las Vegas -- at least by Southern Nevada standards.
But a warming trend on the way, with upper-60s coming in the next two weeks in Las Vegas. In the Reno area, freezing nighttime temperatures are forecast to disappear over the same time.
So, if you're planning to do some gardening, is now the time to do it?
DISCUSSION HIGHLIGHTS:
Southern Nevada didn't see very many below freezing nights this winter. What does that mean for our gardens?
Norm: It means there is less risk to cold-sensitive plants. Citrus trees and other plants that can be hurt by cold temperatures are less likely to have a problem growing in Southern Nevada as the average temperatures increase. But the warming temperatures are a problem during the summer because of the heat load on plants.
Ash trees, California pepper trees and some fruit trees, which all used to grow in Southern Nevada, are now more likely to suffer during the summer.
What has the winter been like in Northern Nevada and when can people there start planting?
Wendy: This year what we've seen is in the lower valley's have been receiving rain. In the last week, some places have received almost three inches of rain, which is unusual. We would like to see more storms so there is more snow in the mountains.
We really don't put any warm temperature crops in the ground without protection until late May to June. But in February or March, we do start planting lettuce and carrots.
There is also a concern for a false spring, which is when it warms up for a few weeks. Many trees, especially fruit trees, start to bloom and then the temperature drops and the flowers die off.
What edible plants can be planted now in Southern Nevada?
Pete: Start your tomatoes and other warm-season crops in March. If you can get them out a little earlier, you can establish them before the hot weather arrives.
Right now, you can put out cold-season crops like cabbages, kale, broccoli and chards now through March.
Caller Rob wanted to know when he should prune his peach and nectarine trees?
Norm: Now is a good time to prune. You don't have to wait until all the leaves are off because the few leaves on the tree now are not providing the tree with much energy.
Be careful with peach and nectarine trees to not over-prune. Don't remove more than 5 to 10 percent of the total foliage in any given year. Fruit trees give us fruit but they are also ornamental part of the landscape. Your main objective with pruning a tree is to have a happy, healthy tree and fruit that comes is the bonus.
Don't fruit trees take up a lot of water?
Norm: We should embrace our desert environment and plant accordingly. There is the idea of a garden oasis, which is a section of the garden that might get a little more water. With that extra water, it is good to get something from it like something edible. Pomegranates and figs thrive in this kind of an area.
Pete: Beyond the mini-oasis, it is important to accommodate your trees and allow for good irrigation and dealing with soils appropriately. Those are ways to conserve water and keep a healthy garden.
Skeeter in Overton wants to know if a tomato plant that froze over the past few weeks, but still looks like it has green around its roots, will come back when the temperatures warm up?
Wendy: If the root system is still intact and not frozen, tomato plants can be perennials. You should take some time to amend the soil with compost because tomatoes take up a lot of nutrients and that means you need to add them back in, especially if the tomatoes are growing in a pot.
Compost is better than fertilizer because you don't have to worry about getting too much of one chemical. You can just let the natural process work.
Mark in Summerlin wants to know what kind of vine to plant to cover up a block wall?
Norm: A couple of vines that I absolutely love that grow quickly, do a really good job and they are very two-dimensional. They stay on the wall. They don't take up yard space. One is hacienda creeper and the other is tangerine beauty crossvine. Both of them self-attach to the wall.
hacienda creeper/photo: ASU.edu
tangerine beauty crossvine/Flickr
Caller Attanasio wants to know if he can grow avocados in his backyard?
Norm: No, they are not cold tolerant. You could put them in a pot in your house to keep them out of chilly weather but they grow into a tree, which means they'll grow out of their pots.
What can be done to stop agave weevils?
Pete: You can plant agave plants that are more resistant to the weevils. So, if you plant one and it dies, don't plant the same variety. Also, don't plant it back in the same hole.
There are some chemicals that you can put around the plant to kill the weevils. The best time to do that is in the fall because that is when the weevil is planting its eggs. It is not necessarily the weevil itself that kills the agave. It is the grub which eats through the root system. So, you might have a weevil but not know it for months.
Norm: Agaves are less likely to succumb to weevil damage with less water. If you can, water your agave six times a year. Just give it a good deep soak once every month or every six weeks in the growing season - March through September.
Also, avoid planting American agave, they seem to be weevil bait.
American agave/Wikimedia Commons
Patrick from Pahrump planted cactus and succulents when he moved out to Nye County, but he didn't realize how much cooler it is than the Las Vegas Valley. The plants died and he wants to know if there are any cold-tolerant cactus:
Pete: There are very good options. Some of the opuntias - prickle pear are part of that species. The other thing I would say is just wait on your cacti to see if they recover when it warms up.
Caller Luciano wants to know how to keep the grass that the previous owners of his home planted green. It is Bermuda grass, which goes brown during the winter.
Norm: Bermuda is a warm season grass so it will die off in the winter weather. There are two ways to green up. One is to plant rye over top of it. Ryegrass is green during the winter and then in the summer, the Bermuda will green up. Or you can paint it. There is turf paint available.
I will say that you can just get used to the lovely tawny color of Bermuda grass in the winter because it will save you water by not having to over plant it with rye.
Mark trimmed the Italian cypress in his yard last year but now they're not growing well and look like they're turning brown:
Norm: With Italian cypress, you don't want to go into the trunk too much because that can provide an opening for bores. But a more common problem with Italian cypress is overwatering. They're native to the Mediterranean, which has a similar climate to ours. I like to move the emitters away from the base of the plant and eventually remove the emitters all together. There are some plants that don't like to get their feet wet and Italian cypress are part of that group.
Jeanie has a raised bed in her backyard but the yard gets a lot of shade. What shade-loving plant should she plant?
Pete: You could prune some of the trees that are providing to much shade to let more light in, but plants like salvias do well in the shade. Other more traditional sun-loving desert plants won't do well.
Shade can be a problem for vegetables. You are going to have success growing them but they are going to get bigger leaves and not has much fruit.
Succulents, aloes and jade plants do well in the shade.
Salvias/Wikimedia Commons
Norm: There is a cool plant called the Grecian pattern plant that loves a lot of shade. As far as edibles, it is generally the leafy greens that do well in shady gardens.
Grecian pattern plant/Wikimedia Commons
Caller Brian wanted to know what mature fruit trees to plant in his yard.
Norm: Don't plant mature fruit trees. If you want mature fruit trees, plant little baby fruit trees. They cost less and take off quicker. Baby trees tend to have better root systems and longer healthier lives. I wouldn't plant anything bigger than a 15 gallon.
Plant pomegranates and fig trees and you can plant them right now. If you plant later, you need to keep that original root ball moist.
Andrea wants to grow strawberries for her family of five:
Norm: The strawberry pots are going to dry out too quickly. Strawberries want a lot of water and they also like nice rich, organic soils. The best way is to find a pretty shady spot and have a raised bed and bring in or build a really nice rich, organic soil. And then your success will be moderate. I've never seen huge quantities of strawberries here.
RESOURCES:
University of Nevada Cooperative Extension Clark County
University of Nevada Cooperative Extension Horticulture Program
Mountain States Wholesale Nursery
International Society of Arboriculture
UNR College of Agriculture, Biotechnology and Natural Resources
From Nevada Public Radio: Desert Bloom
Norm Schilling, Schilling Horticulture; Pete Duncombe, Trident Landscaping; Wendy Hanson Mazet, an arborist and master gardener, University of Nevada Cooperative Extension.