Spring Is Closing In - What Should You Be Planting Now?

By Joe Schoenmann

Published February 18, 2021 at 10:50 AM PST

Enjoy this gardening show from last month, then listen LIVE at 9 a.m. Thursday, March 18 when Norm and Angela return to answer more gardening questions on KNPR and KNPR.org.

Gardening is always a major focus in Las Vegas; people simply like trying and succeeding in growing things in the desert.

It’s become even more of a focus to some as the price of certain grocery items increases.

There are always questions of timing, though—because timing isn’t even the same anymore. Heat seems to come earlier and last longer each year.

So when do you plant? How do you care for your trees? Have things already changed so much that your planting habits have to change, too?

Fortunately, Norm Schilling and Angela O’Callaghan have forgotten more about planting and gardening than most of us will ever know.

DISCUSSION HIGHLIGHTS:

Is right now a good time to plant tomatoes?

Angela O'Callaghan: It is still a little bit chilly but you want to have them in the ground, and I'm talking about transplanting plants that have a good four, maybe more, sets of true leaves. You want to have them in the ground by the middle of March.

Don't try planting tomatoes after mid-March because, by the end of June, you might as well just cut the tomatoes back and wait for the fall. They are warm-weather plants, not hot-weather plants

How about onions?

O'Callaghan: You want to put them in now because they take a long time to grow, and you don't want them growing in the hot weather when they are just as likely to bolt, meaning they'll produce a flower stalk, and the onions will be pretty much unusable.

What about potatoes?

O'Callaghan: Potatoes are also early but be really careful that it is a type of potato that will actually grow here. Potatoes that do well in Idaho are the type that do well when it's cooler and the summer days are longer. Look for a variety that does well in Arizona or Texas.

Em received bare-root dogwood and redbud trees from the Arbor Society for National Arbor Day and wanted to know how to plant them.

Norm Schilling: So, mail that to your cousin in Georgia. It was great that you joined, but they sent you stuff that just does not want to be in Nevada.

O'Callaghan: There are so many trees that can grow in the rest of the country but they just don't do well here.

Schilling: Redbud can do well here. It's a small tree. It's a cute little tree so that you should plant in your yard.

Redbud tree/Wikimedia Commons

Sharon moved into a house with a peach tree. The tree had a net over. She removed the net but wants to know how to prune it.

Schilling: The netting was to protect the fruit from birds. You can put the netting back up or you can buy little protective cloth bags to put over individual fruit.

As for the pruning, peaches are stone fruit. You should never prune a peach, an apricot, an almond, a plum hard. It can stress it out. Five percent total foliage removal - maybe 10 percent. You want to take out branches that cross or rub, which can be done before the tree leaves. After it leaves, take out all dead wood by cutting at the dead tissue and leaving all live tissue alone.

AJ has a backyard with a lot of Bermuda grass that he wants to get rid of:

Schilling: Kill it - chemically. The only way to take out Bermuda, unfortunately, is chemically. Please know, that by nature, I'm very organic and eschew the use of pesticides as much as possible but there are times you got to bring out the artillery.

Bermuda is a warm-season grass. The only way you can kill it is when it's actively growing, which is the months of basically June, July, August, September. The more actively growing it is the better you can kill it and use Roundup. Make sure to follow the instructions on the container.

O'Callaghan: We have to remember that Roundup will kill plants. People can't be confused and think they're just going to kill the Bermuda.

Rachel bought a house with two lemon trees on the side but she can't walk down that side of the house because of the thorns on the trees. Can she move the trees?

Schilling: No. You can trim citrus back hard, losing up to 30 percent of the total foliage. But you can't move a mature or even a young lemon tree without damaging it.

O'Callaghan: You can't move a lemon tree without damaging its root system.

Will succulents grow in Southern Nevada?

Schilling: Sometimes

O'Callaghan: It depends on when it's getting light. If it's getting afternoon light, and it's against a wall that wall is also going to fry that plant.

Schilling: You buy those cute little succulents at Loews. They typically want some shade. They want to dry out in between watering, but my rule of thumb is for every 10 you buy in a year, you'll probably have three. And that's okay because they're $1.19 each and some will do better and some won't. It's not a big loss. They generally want shade, and it's really important that you don't over-water them.

Jonathan wants to know the best way to control aphids on his crepe myrtle:

O'Callaghan: Aphids are prolific. The females don't need males to reproduce and are always reproducing. The best option is to take a hose to the plant and blast them off. You can also use diluted soap water, which will help keep the pads from sticking as well, and then rinse the soap water off.

Aphids/Wikimedia Commons

Schilling: I look at aphids as the meat and potatoes of the bug world. If I have a few aphids, I don't do anything. I just think: Well, predators are going to come in. If it gets heavy, blast them with water and drown them.

If you use soapy water, it will also hurt predators. Aphids reproduce really quickly but predators like spiders and lacewing bugs reproduce slowly. So, if you get rid of the aphids and predators, then the aphids will return quicker and the population will explode and you're worse off.

Callaghan: Whatever you do, don't use an insecticide.

Carol has three large mesquite trees in her yard and wants to know when to have them pruned:

Schilling: You can prune desert trees pretty much year-round. However, sometimes pruning not done well is more damaging to a tree than it is good for a tree. Whoever is doing the work, talk to them about credentials, what they know, what training, what education, do they have certification. Because I see a lot of pruning work that is subpar, and that's being kind of generous.

Kerry has a pomegranate tree and wants to know how to tell when the fruit is ripe.

Schilling: Pomegranates ripen late fall - November or December - depending on where the tree is located. When the fruit starts to split, it is ripe. The basic rule of thumb is the rind naturally splits itself and that's when it's telling you that they're ripe.

O'Callaghan: But don't let the fruit sit on the tree with that split too long because there is a bug that loves pomegranates in Southern Nevada. If it gets into the fruit, it will reproduce and it is one of the more disgusting things you'll see.

As soon as you see it starting to crack, that's when you're going to start looking at whether it's ripe or not.

Tom has four large rosemary plants that are taking a large portion of his yard. He wants to know to prune it back:

Schilling: Well, move slow because there are probably bees on it. They have a dead zone. If you cut into the dead zone too much, they won't regenerate. Basically, you want to cut where there is live tissue.

As the outer foliage grows, the inside is not getting any sun. So, the foliage dies off. If you cut a rosemary back into an area where there is no foliage, the foliage won't come back.

Marion has two fruitless mulberry trees in her yard and the roots are starting to push up the cement of the patio and the cinderblock wall between her yard and her neighbors:

Schilling: Mulberries are big trees by nature, which produce big roots. If you prune it back really hard, you are really damaging and beginning the process of death and decline of that tree.

The root system provides stability for the tree. If you try to prune the roots, you can do a lot of damage and increase the likelihood that the tree could topple over.

I hate to tell you but you kind of have to choose between your mulberry tree and the driveway and the wall. I'm personally rooting for the mulberry tree.

When choosing a tree, think about the mature size of the tree.

O'Callaghan: We never do. We think: 'Oh, look at this cute little tree. It's five feet now, maybe it will get to be 10 feet.' Then you look it up and you see, 'This thing can get to be 35-40 feet tall!'

Bob wants to know if he can move the shoots from his timber bamboo to another part of his yard:

O'Callaghan: As long as it's a healthy shoot and you've got roots, you should be able to take it and transplant it. Just remember, it's bamboo so it's going to want a fairly rich soil, pretty high nitrogen, and good watering.

Schilling: You're going to want to do it - I think this is generally true of most things - do it in cooler weather. Also realize, that often when you transplant plants, they show stress. They show dieback They show that you're not happy, but as long as you have some live tissue it can recover.

Michael has a dwarf Meyer lemon tree that flowers but doesn't produce fruit. A few years ago, he moved it from a pot to the ground.

Schilling: Does the fruit set and turn black - little tiny lemons die off before they get big?

Michael: Yes. Some of them get to that stage, but most of them fall off in the flower stage.

Schilling: That's normal that a lot of flowers aren't going to produce fruit. I think what's happening is your fruit is growing a little bit and then it's blackening and dying off. It is probably a water resource issue. It needs a lot of water to produce that fruit

This a common mistake. When you put in the ground, you put a few emitters on that root ball but know that trees in the wild spread their roots out like the spokes of a wheel and those roots extend one-and-a-half to four times canopy diameter.

The point is - give it extra emitters out around at least to the drip line and even beyond. The roots will respond and start growing into those wetting patterns and they like a lot of fertilizer.