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Summertime And The Planting Is Easy -- Or Not


Natalie Cullen

It’s a dry heat, sure, but none of us want to spend much time in it when it’s 105 or more. That is, unless outside means submerged in a swimming pool.

But imagine how your outdoor plants feel.

Plants, gardening and all things chlorophyllic -- horticulturists Norm Schilling and Angela O'Callaghan join us to answer all your questions about summer gardening in this blistering heat.


On edible leafy plants that do well: 

Angela: Kale, Swiss chard, New Zealand spinach, which is not actually a spinach but tastes a bit like spinach.

Norm: In the early season, you can do regular spinach and lettuces as well but once it gets hot they turn bitter.

Other edible plants: pansies, pineapple guava.

Pineapple Guava blossom/mizpattytoyou/Flickr 

On self pollinating:

Angela: There are number of ways you can do it. Professionals do one of two things. They'll either take a small artists paint brush, rub the tip of the paint brush on the stamen of one flower, get some pollen off it, put it onto another flower. Or they will take an electric toothbrush and just zap the plant a little bit so you are loosening the pollen.

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Caller Sean recently planted new drought-tolerant trees. How often should he water them?

Norm: You should water them pretty frequently right now to get them started, because these desert plants are in a pretty limited root ball. You probably need to water every other day and give it a good deep soak. But start backing off the frequency pretty soon. Once we hit the true monsoon season in August... water it less often. 

You need to get the root system out from the base of the tree into the surrounding soils. If you don't already have emitters three or four feet out in all directions, add them. Or do deep soaking with a sprinkler. 

Eventually, in a couple of years desert willow, acacias, Palo Verde, mesquites, African sumacs, you can water three of four times a year. They are really, really drought tolerate. 

On African sumacs losing their leaves:

Norm: They are semi-summer deciduous. So most deciduous trees drop their leaves in the winter. That's their response to that season. Some of the desert trees will respond to hot weather by dropping some of their leaves. It's their coping strategy. They're having a hard time getting enough water up into the leaves. 

This time of the year its normal for those leaves, typically older leaves to yellow out and drop. There is nothing to be concerned about. 

Caller Skeeter wanted to know when to harvest onions:

Angela: You don't want to let them get to flowering. When they flower, they send up a shoot that goes all the way through the bulb. That's considered really bad.

Plant them early. They take about six months really to grow, to fully form a bulb. If you're looking for a one inch bulb or two inch bulb, you can harvest them in spring. If you what until they've flowered, you've waited too long.

On watering cacti

Angela: It really depends on the cactus. If it is a cactus that is really well established, they you only have to water it very rarely. Like desert trees, cactus are water gluttons, because they say, 'I'm not going to get it. I better grab it now.'

Norm: I think it's a good idea not to water them at all during the cool seasons, starting in October through February or March. If you have an irrigation system and they're on the irrigation system... you can put on a shutoff valve on the end of tubing. 

Caller Will wanted to know how far apart fruit trees should be planted:

Norm: It depends on the mature size of the plant. It is really important to know or keep the information about what the varieties are. Dwarf peaches grow as little as five or six feet. Semi-dwarf typically get up to 10 or 12, maybe 15.

Angela: The important thing is to look at how wide that canopy is. Most commercial growers, who are growing on dwarf root stock, that's how most fruit trees are done, they grow at least eight foot centers. So you make sure you have at least eight feet between your plants.

Caller Allyson wants to know the correct way to pollinate squash:

Angela: The thing about squash blossoms is you have to do that very early in the morning. Squash blossoms only last about a day. That pollen dries out really fast. So as long as the pollen is early and fresh that is when you can use it. If it's in the afternoon, you've kind of missed the boat.

Norm: We all love flowers but having these desert flowers things like angelita daisy or Indian blanket flower or my favorite shrubby dogweed, having them in your garden attracts pollinators and so they'll also go visit your fruit trees and your veggie crops. They have really, really long bloom seasons and a lot of insects that they attract not only are they pollinators they also double as predators.

 Angelita daisy/Desert Rivers Audubon/Flickr

Indian blanket flower/Chad Sparkes/Flickr

Shrubby dogweed/Wiki-commons

On citrus trees and tomatoes:

Norm: Cirtus needs quite a bit of sun. If you can find a place where it gets lots of morning sun and then some afternoon shade that's even better. Having it up against a south facing wall, let's it have some additional radiated heat from the wall in the winter time.  

Angela: First what you have to remember is don't plant them in June or May. You plant them in March, because it's just not the place. Tomatoes are warm season crops not hot season crops. The ones that we find do the best produce a smaller fruit because the smaller fruits tend to mature faster. So grape tomatoes, cherry tomatoes, 4th of July hybrids, Rutgers heirloom. 


University of Nevada Cooperative Extension

Master Gardeners

Mountain States Wholesale Nursery

High Country Gardens

International Society of Arboriculture

From Nevada Public Radio: Desert Bloom


Norm Schilling, horticulturist at Schilling Horticulture; Angela O'Callaghan, associate professor in social horticullture at the Nevada Cooperative Extension.


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