Protect Yourself and Your Plants During the Summer Heat

The heat is on here in the High Desert. During these hot summer months, I try to get out and do my gardening chores early in the morning to avoid the intense heat of the day. Since it is easy to find yourself out in the yard longer than intended, it is a good idea to apply a good sunscreen, and wear a hat and light-colored loose-fitting clothes to help prevent sunburn. And, don’t forget to stay hydrated by drinking plenty of fluids – my preferences are water, unsweetened ice tea or coconut water.

Heat and sunlight not only affect gardeners, they also have an effect on plants.

Leaves can become sunburned and begin to get large yellow patches that turn gray or brown in the center. If plants showing signs of sunburn are in pots or containers, move them to areas where there is more afternoon shade. If the plant(s) are planted in the ground, it may be necessary to erect some form of shade cloth protection on the south and west sides of the plant. If certain plants become too stressed in the summer, it might be a good idea to consider moving the plant to a more suitable location in the fall or early spring, or add protective, shade-giving plants to the existing landscape.

Sunscald on trunks can lead to disease problems and even death. This most often happens on young trees that have not yet developed a true bark. To help prevent sunscald, apply a coat of white interior latex paint that has been mixed with water to make a half paint- half water mixture – sunscreen for plants. There are also fabrics available at nurseries and garden centers designed to wrap around a tree trunk to help prevent injuries, including those caused from too much sun.

Some plants may show signs of drought stress, which appears as yellowing and browning leaves, but not in patches like sunburn. Plants will also begin to wilt. Make sure that trees are getting deep watered to a depth of three feet, shrubs to two feet, and ground covers to one foot. It is best to deep water less often than to frequently water just the surface. Also take note that most of a plant’s water-absorbing roots are located around its dripline (edge of its canopy), so make sure to apply most of the water in this area rather than around the trunk or stem. Once the soil has dried to a depth of two to several inches, apply more water.

Some plants prefer dry summers and are prone to rot problems if given too much water in the spring. Many of these plants are our California native species, which are adapted to winter rainfall and dry summers. If such a plant is showing signs of wilting, and it has been watered regularly throughout the summer, check to see if the soil is moist. If it is moist, discontinue watering until cooler weather comes along and see if it begins to improve. These types of plants can be susceptible to root rot fungi that become damaging when conditions become warm and moist. Wilt symptoms appear because the rotting roots can not longer take up the necessary water. Allowing the soil to dry out a bit can help promote new roots to grow and the plant to recover.

So remember that plants can be affected by the summer heat just as we are. Sunburn and dehydration can be prevented if care is taken to make sure that adequate shade, sunscreen and water are used. Since the amount of water we use is an issue here in the desert, it is a good idea to consider the use of native and desert adaptive landscape plants that don’t require lots of summer irrigation.

Helpful Hints for Summer Gardening

Well, the summer heat will be settling in soon and some of the plants that were doing well in the spring will begin to look a little parched. The best seasons for plant growth here in the High Desert are spring and fall, but we still need to keep our plants and yards healthy year-round.

Roses are among those plants that could use a little extra help in the summer. Here are a few hints for your roses to perk them up a bit and help them to perform better when fall arrives:

Water deeply - A couple of times a week should be sufficient, maybe a little less depending on your specific soil type.

Mulch around the root zone - This helps retain moisture, but also helps insulate the root zone from the intense heat.

Deadhead - Removing dead flowers is a form of summer pruning.

A little fertilizer wouldn't hurt - According to Botanica's Roses, they should be fed in the spring and again in summer. Use a good rose fertilizer applied to the soil around the root zone - avoid foliar sprays, which can burn the leaves.

Different rose enthusiasts have various methods for growing gorgeous roses - If you know a successful rose grower, ask them what they do. More than likely, they will be happy to share their knowledge with you.

Bedding plants always add a nice touch of color around the yard. The problem is that many of them that were looking great in the spring, don't look great in the summer. Pansies, sweet peas and calendulas, for example, don't like the heat of summer, unless you have a cool, partly shaded microclimate somewhere in your yard.

There are numerous bedding plants available at most garden centers/nurseries that do just fine in the summer. If in doubt about what to choose, ask a knowledgeable sales person what works well in this area. Some of my recommendations include daisies, marigolds, petunias, scarlet sage, lobelia, zinnia, coreopsis, cosmos, pincushion flower, verbena, nasturtium and sweet alyssum. This is certainly not a complete list, and you may find some others that work equally well or even better.

Some hints that will keep bedding plants performing is to water regularly, and remove the dead flowers to encourage new ones to bloom. If the plant starts looking straggly, prune it back to about half its size - within a week or two, they will be back in full bloom. They can also benefit from some fertilizer. Again, mulching can help retain moisture in the soil. Pests such as aphids can be taken care of using a blast of water from the hose or spraying with a light solution of water and Ivory dish soap.

If there is some concern about bedding plants using too much water, just use a few bedding plants here and there for a splash of color. You don't have to plant the entire yard with them.

With the Memorial Day and Fourth of July holidays coming up soon, you could get a little patriotic thing going by planting various red, white and blue flowering plants around the yard or in containers.

If choosing to plant in containers, choose insulated or light colored pots, and place them in an area where they are shaded from the hot afternoon sun. Darker colored containers, especially those exposed to the sun, can quickly heat up and cook the roots of your plants.

Colorful Perennials

Ozark Coneflower

Summer is almost here, and with it is a nice colorful landscape thanks to a variety of perennials I planted over the past couple of fall seasons, which happens to be the best time for planting here in the High Desert. Perennials are a great addition to the landscape because they come back year after year so there is no need to replant every year like you have to do with annuals. Many perennials die back to the ground during the cold winter and resprout in the spring, while others may simply lose their leaves during the winter, and still others may continue to bloom nearly all year.

If you are looking to put in a few perennials come fall, spend some of the summer doing some research and planning on exactly what you want.

Angelina Stonecrop

There is wide array of perennial plants to choose from, even varieties that thrive in our High Desert climate. They come in many shapes and sizes, leaf colors, flowers, and many attract hummingbirds, butterflies and bees. By researching what plants you want; it is possible to create a perennial garden that has something blooming nearly all year.

Blanket Flower

One of the books I enjoy on the subject is, "Perennials for the Southwest" by Mary Irish. It offers information about plants that flourish in arid climates. The author clearly recognizes that there are different climates throughout the Southwest and divides them into three distinct zones, our area being considered a mid-elevation desert that is extremely arid with hot summers and cold winters.

The book has a section on designing with perennials, which can be very helpful with visualizing how a selection of perennial will actually look in a landscape setting, and helps to plan for year-round color.

Another chapter goes over the care of perennials such as how to manage the soil, when to plant, pruning, pests and beneficial insects, and everything in between.

Autumn Sage

The best part of the book – plant descriptions – encompasses nearly two thirds of the book. It features a plethora of perennial species along with numerous color photos, and descriptions of when they bloom, mature size and form, what type of sun exposure they prefer, their cold hardiness, and suggestions for incorporating them into the landscape.

This great book can be purchased online at

http://www.timberpress.com/books/perennials_southwest/irish/9780881927610, from Amazon, or in bookstores.

Agastache neomexicana

Among my favorite perennials are penstemons, sages/salvias, blanket flowers, day lilies, society garlic, cone flowers, coral bells, Angelita daisies, Agastache, cone flowers, and bee balm, just to name a few. Most are not too difficult to find. On one visit to The Living Desert in Palm Desert, I was able to find a huge selection of desert-friendly perennials at their nursery. It's a great place for purchasing otherwise hard-to-find desert adaptive plants. Some of our local nurseries carry a number of common perennials. One of my favorite online nurseries is HighCountryGardens.com.

Purple Coneflower

Remember when making selections, make sure the plants will handle the High Desert climate by reading their descriptions, tags, labels or signs. If in doubt, check with the Western Garden Book. Remember the High Desert is generally in Sunset Zones 10/11 or U.S.D.A. Zone 8b.

Day Lily

Angelita Daisy

Salvia

Watch out for Blossom End Rot

Among the many different kinds of veggies that I planted in my garden this year, tomatoes are one of my favorites. I planted several different heirloom varieties including Brandywine, Blue Berries, Beefsteak, Chadwick Cherry, Roma, Green Zebra, Moneymaker, Yellow Pear, Arkansas Traveler, Bradley, Black from Tula, Indigo Rose and Orange Plum — all are doing very well so far – but sometimes, heirlooms have less resistance to diseases and disorders. In the past, one of the issues for my tomatoes was Blossom End Rot. It has been a few years since this was a problem, but those varieties most affected were Beefsteak and Roma.

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When the weather warms up, the tomatoes begin to set fruit, but as the tomatoes grow they sometimes develop Blossom End Rot. The symptoms of Blossom End Rot are found at the blossom end of the tomato (opposite end from the stem). The area gets a water-soaked appearance, which gradually gets bigger and turns brownish or blackish and looks leathery, and the end of the tomato will appear flattened. There are a number of causes for Blossom End Rot, and all are easily remedied.

The most common cause is calcium deficiency. When the weather gets hot and dry, the tomato plants draw extra water and nutrients to their leaves, which can starve the fruits of calcium. Calcium can also be leached away with heavy rainfall or excessive watering. We don’t have a big problem with heavy rainfall here in the High Desert, but it is easy to readjust the amount of irrigation water the plants receive. The soil should be moist, but not soggy. Adding a quality low-nitrogen fertilizer that has calcium in its list of ingredients can help to boost the calcium available to the plant. Too much nitrogen causes the plant to have too much green growth at the expense of the fruits.

Also, if the soil’s pH is too high or low (best range is 6.0 to 7.0), the calcium in the soil may not be available to the plant. You can add horticultural limestone/lime to soil that has too low of a pH. If the soil is not excessively acidic, add some gypsum. If your soil has too high a pH, add sulfur according to the package directions. If your garden is like mine and contains no native soil at all, the pH could be a bit on the low side. If your soil is mostly native desert soil, it may be a bit on the high side. Test your soil and adjust it accordingly.

Another problem that can cause Blossom End Rot is uneven watering — the soil gets really wet after watering and dries out too fast because the soil does not retain the moisture sufficiently, which is a common issue with our High Desert soils. The best remedy is to add a thick layer of organic matter such as compost to the soil and cultivate it carefully, trying not to disturb the plant’s root system. It should help to provide good drainage, while helping the soil to maintain a more even moisture level.

In the case of my Beefsteak plant, it was probably suffering from a couple of calcium deficiency problems that were causing the Blossom End Rot condition. Although the plant received adequate sunlight, it was receiving a little more shade than the other tomato plants, but I had been watering it just like the others. There was a chance it was getting over watered, and perhaps leaching the calcium from the soil. This variety may also have been less resistant to Blossom End Rot than my other tomatoes.  I cut back on the watering just a bit because I noticed the Blossom End Rot occurred after I watered the garden heavily to make sure it didn’t dry out while I was on a weekend get-away. The rest of the garden dried out sufficiently, but not as much where this tomato plant was located.

My soil is probably 99 percent organic matter and contains no native desert soil at all, so there was a chance the pH was a little low. I should have done a simple pH test to know for sure. A purchased a bag of organic bone meal, with an analysis of 4-12-0, did take care of the problem. There is a small amount of nitrogen and a fair amount of calcium in the ingredients list, plus the extra phosphorus helps the plant to have a stronger root system and get more blooms, thus more tomatoes. This, along with watering a little less, not only remedied the calcium deficiency problem, I got more tomatoes to boot.

Irrigating My Vegetable Garden

It is that time of the year when my vegetable garden is getting into full swing. All of my warm-season veggies are planted and beginning to grow. It does come with a certain amount of time needed to keep it watered enough so the plants will grow and the seedlings don't dry out. Hand watering is a form of therapy for me, and it allows me a way to monitor the garden more closely every day, but like many other people, the time I can put into watering the garden is limited. Also, although watering the garden is my "thing" it is not necessarily what my husband or house sitter wants to do when I (or we) go on vacation.

So, last year, in order to save some time, and to eliminate the need to pay someone to water for me when I am away, I decided to install an automatic watering system that is water efficient and easy to use. There are so many products on the market - in stores and online. There are drip irrigation kits, and the materials to create your own design. There are also soaker hoses - just the hoses, or kits where you can customize your system to whatever configuration you want. Each of them has its own merits and flaws, which leaves it up to the user on what they want to work with.

I was looking for a system that was easy and quick to install with minimal tools, and something that only watered the root zones of the plants to minimize water usage. I ended up choosing a customizable soaker hose kit that I got from Gardener's Supply Company online - www.gardeners.com - called Snip-n-Drip and the only tool required is a pair of scissors. They offer these kits for raised beds, garden rows, landscape beds, and container gardens. I got the one for row gardens even though I am using it on my raised beds. I also purchased kits for my container plants, too.

Inside the box are 25 feet of half-inch garden hose, 100 feet of half-inch soaker hose, three 3-way connectors, one single connector, one faucet adapter, and four end caps. This is enough for about four six-by-four raised beds or four rows at 25-feet long. I purchased four kits to adequately cover my 14 raised beds. It took me less than half a day to install the system to all of the beds. The raised bed kits have little corner adapters to keep the garden hose portion running along the ends of the beds, down the sides, and at ground level between beds. Since I chose to get the row-garden kits, I have to step over the hoses that are between the beds, which saved a little bit of cash.

I ran the hoses down the length of the beds. At each bed, I cut the hose with a pair of scissors and attached a three-way connector - garden hose attached to two of the connectors and soaker hose to the third. I used about 25 feet of soaker hose per bed and curved it around to make sure each plant would get watered. At the end of each soaker hose section I installed an end cap. To help keep the soaker hose lying flat, I used some wire hook stakes that I picked up at Orchard Supply Hardware. The final bed got a single connector from the garden hose to the soaker hose. The beginning end of the garden hose got a faucet/hose adapter so that I could attach it to the end of a hose that ran up to the faucet at the house. I have two sections of raised beds, so each section got its own irrigation system. To make it even easier, I attached the hoses to a two-outlet faucet timer so that my newly installed watering systems could turn themselves on and off.

There are many different timers on the market and over the years I have tried out many of them. For the most part, they were difficult to program ... that is until I discovered the Orbit faucet timer at Lowes. It is so easy to use, and is available in either one or two outlet versions. They use two AA batteries, which usually last the entire summer season. I have been using them for a few years now to operate my drip irrigation system that waters all of my trees and shrubs. If is getting a little late in the season, I usually change the batteries if I am going away to eliminate any potential problems for the house sitter. When winter comes, I just remove them from the faucet and store them in the garage to keep them from freezing.

The system has been operating for a year now and I am very happy with how it works, and the extra time it gives me to take care of other obligations when I need to. The only modification I made was to split each of the garden areas into two zones each because the water was not making it to the very end section in sufficient amounts.

The Dreaded Tomato Hornworm

Now that my tomato plants have been planted, it won’t be long before the dreaded tomato hornworms begin to show up and start busily munching away. Tomato hornworms can also be a problem for plants related to tomatoes such as eggplant, peppers and potatoes. One day in the not too distant future, I’ll trek out to my veggie garden and quickly notice the tell-tale signs of these hungry invaders – the munched foliage at the ends of the branches, and not far below the missing leaves will be the droppings (caterpillar poo).

I'll start looking for the nasty green worms, which takes a while because they blend in perfectly with the stems and foliage. I try to catch them early on so there is minimal damage to the plants. Last year, I found four hornworms, a couple of smallish ones and two rather large ones, early in the summer. The small worms were only about an inch long, which means the eggs they came from had just recently hatched. They have ravenous appetites and eat so much very quickly that they grow fast. If I had taken a couple days longer to detect them, they could have easily been the size of a finger, and perhaps devoured much of the plant they were on. Later in the summer, I found many many more – it was an especially bad year for them. I did find most them while they were on the small side, so damage to my plants was minimal.

How do you recognize a tomato hornworm? How do you manage them? Here’s a little information from UC Davis’s Web site (http://www.ipm.ucdavis.edu/PMG/GARDEN/VEGES/PESTS/hornworm.html):

Tomato hornworms of all sizes have a distinctive horn at the rear end. If you find them early on they are small, but mature caterpillars are very large – up to 4 inches long. Tomato hornworms are likely to be the largest caterpillars you will see in the vegetable garden. Their striping pattern makes them hard to spot despite their size. Large, black droppings on the ground beneath tomato plants or on the leaves below where they are feeding usually indicate the presence of hornworms. The adult moths that are responsible for these worms have a wingspan up to five inches.

Damage by hornworm larvae (the worm/caterpillar) is usually most common in midsummer, but there may also be a small population peak in the late summer. Infestations tend to be more severe in warm inland areas such as the High Desert. The larval form is the only stage that causes damage. The eggs are laid singly on leaves. The larvae feed and grow, and then burrow into the soil to pupate. The adult/moth develops over the winter and emerges and the cycle continues. Entire leaves and small stems may be consumed by the larvae. Large pieces from green or ripe fruit may also be chewed.

To manage hornworms, handpick or snip hornworms with shears. Hornworm eggs can be attacked by Trichogramma and the larvae by Hyposoter exigua – two types of parasitic wasps – which can be purchased through various catalogs and released into the garden. There are also several general predators such as praying mantids to help keep populations under control. Bacillus thuringiensis (Bt) or spinosad are effective against smaller larvae. Discing or rototilling after harvest destroys the pupae in soil and helps prevent adults from developing.

I tend to handpick the hornworms, and then feed them to my chickens. It is important to keep looking and not assume there are only one or two. It is best to look for them early in the morning, because they tend to hide out during the heat of the day. Look along the stems and under the leaves, especially near the ends of the branches and near where damage has been found. If you notice the droppings, look above that area. Tomato hornworms used to scare me so I would snip them with shears, but the disgusting green goo they leave behind is not very appealing. I eventually learned to put on a pair of gardening gloves and simply pick the worms off the plant. Chickens enjoy feasting on tomato hornworms, so if you happen to have chickens, it’s a great way to dispose of the worms once you have removed them from your plants. If you notice the eggs or pupa (cocoon), destroy them before they develop into the dreaded hornworm.

Beneficial Insects and Other “Bugs”

Adult Lady Bug

Lady Bug Larvae

Now that the weather is warming up a bit, you may start to notice a few more “bugs” showing up in your landscape or garden. But, do you know which of these bugs are actually bad, and which ones are beneficial?

Insects and other creatures can be a desirable part of the landscape and garden because they help to reduce the numbers of plant damaging pests. Some of them are predators, while others might be parasites. Sometimes, we might recognize the adult insect, but are unaware that there is a larval stage, or what the larval stage looks like – this is certainly the case with lady bugs.

We all know what a lady bug looks like – red, sometimes yellow, with or without black spots. They eat lots of aphids and other small soft-bodied insects. But, did you know that their larvae are even more ravenous? Do you even know what they look like? Lady bug larvae are small, maybe up to about a half-inch in length, “alligator-shaped,” and black with orange spots.

Another common beneficial insect is the green lacewing. They are very delicate, light green insects with rather large lacey-looking wings. Their tiny whitish eggs are laid singly on the end of a hair-like filament, and can be found on leaves. I commonly find them in my apple trees. The very hungry larval stage resembles a tiny alligator and is usually a pale color with darkish markings.

Praying mantids are another somewhat helpful insect. They are usually two to four inches long at maturity and are usually yellowish, green or brown. Their front legs fold in a “prayer-like” manner. The immature mantids look like tiny versions of the adult. They will eat any insect that may cross their path, even the good ones, which is why they are only somewhat helpful.

Spiders, although creepy to many people, are also beneficial because of all the insects they snare in their webs. Of course, we don’t want to keep the dangerous spiders such as the Black Widow or Brown Recluse in our gardens, but if you determine that the spiders you see are harmless to people and pets, keep them around for insect control.

There are numerous beneficial “bugs” in the garden that help pollinate such as bees and hoverflies. Hoverflies, which resemble bees, are often seen hovering or nectaring at flowers – the adults feed mainly on nectar and pollen, while the larvae eat a wide range of foods. Depending on the species, the larvae may eat decaying plant and animal matter in the soil or in ponds and streams. Or they prey on aphids, thrips, and other plant-sucking insects.

Other beneficial insects are parasitic, mainly tiny wasps or flies that lay eggs either in or on specific host insects. The eggs hatch and as the larvae develop, they consume their hosts.

If you don’t have these beneficial creatures in your yard naturally, they can be purchased at nurseries and through garden catalogs, and then released according to the package directions.

There are a number of books on insects that might help you to identify the different damaging and beneficial species. Among my favorites are “Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control” by Mary Louise Flint and Steve H. Dreistadt; “IPM for Gardeners: A Guide to Integrated Pest Management” by Raymond A. Cloyd, Philip L. Nixon and Nancy R. Pataky; and “Garden Insects of North America” by Whitney Cranshaw. Each of these can be purchased/ordered through local bookstores or at amazon.com.

A great website to help identify beneficial "bugs" is  http://ipm.ucdavis.edu/PMG/NE/index.html