Tomato Leaf Roll

Several days ago, on June 12, we experienced a cloudburst that dumped well over an inch of rain in a short amount of time. After sharing a few photos with friends on Facebook, many that live in the same basic area commented back that they had only received a few sprinkles and were amazed by the amount of rain shown in my photos. This is kind of normal for the High Desert – a downpour in an isolated location and little to no rain in other near-by areas. Yay, it was my turn for some free water!

Although almost all of the runoff was diverted from my veggie garden area, parts of the area were watered a little more than needed. The garden area held up remarkably well, but one of my heirloom tomato plants (Black from Tula) ended up with an environment disorder – tomato leaf roll.

The symptoms of tomato leaf roll are firm and leathery leaves; and the lower leaves roll upward. This occurs in wet spring conditions, which is usually not a huge problem here in the desert.

There is no need to worry about it though, as the symptoms will disappear when the temperatures get warmer (they have), and the soil dries out (working on that). Normal growth will resume and future fruits will not be damaged.

For more information about other tomato disorders, diseases, and pests, visit ipm.ucdavis.edu.

Containerized Canna Adds a Tropical Effect to Patios and Pool Areas

A couple years ago when I was adding furniture and new containerized plants to my front patio, I decided to buy a Canna for its bold colors and tropical effect. I had not purchased one before because the High Desert is not in the proper zone according to the Sunset Western Garden Book. Some other research revealed that it would grow in USDA zones 8-11, which would work since this area is in USDA zone 8b. Canna certainly does not belong in a drought-tolerant landscape, but in containers where water use can be limited, or near ponds and pools, it is a beautiful and dramatic addition.

Cannas bold effects come from its huge leaves and striking flowers that are available in many different colors depending on the specific variety. The one I have right now is called ‘Tropicana’ and it features brightly colored variegated leaves with hot orange blooms. It flowers intermittently early summer through fall, but the foliage is so pretty that I enjoy it whether it has flowers or not. A couple of other varieties I would like to get include “Black Knight’ with blackish bronze foliage and deep red flowers, and ‘Nirvana’ which has white and green striped leaves and butter-yellow flowers. There are many varieties available in nurseries or through catalogs and online. 

 Cannas prefer full sun, plenty of heat, and just about any type of soil, but because of the large leaves they need to be somewhat protected from the wind. They are heavy feeders, so they need regular fertilizing and plenty of moisture. Cannas can benefit from a layer of mulch to help the soil retain moisture. Some varieties get quite tall, so staking them might be necessary. Removing faded flowers encourages the plant to produce more blooms. If Cannas get a little ratty looking during the summer, they can recover quickly by cutting them back to the ground and adding fertilizer/compost and water. 

After the fall frost blackens the leaves, the stems should be cut back to ground level and then covered with a heavy layer of mulch. I usually cut back my containerized plant and place it in the garage for the winter, watering occasionally to keep it from drying out. It has grown quite a bit over the past two years so this fall I will pull it out of the container and divide the bulbs, which means next year I should have three or four containers of this beautiful Canna. 

Watch Out for Squash Bugs

For whatever reason, this year seems to be the year for a variety of garden pests, among them, an encounter with squash bugs – so far only one, but I will need to keep an eye out for more. A couple of years ago a friend from work had a huge infestation of them, and she was bothered with them again last year. I had been lucky in that I had never had them in my garden until last year, where I found a few adults, but no eggs or nymphs – I kept watching closely for evidence of these plant-damaging invaders and squashed (no pun intended) them whenever one made an appearance.

According to the website - www.ipm.ucdavis.edu – squash bugs (Anasa tristis) are a common vegetable-garden pest. They feed on the plant by piercing the leaves and sucking the plant's sap, which results in wilting and potential death of the plant. They target plants in the curcurbit family – pumpkins, squash (summer and winter varieties), melon and cucumbers.

When the adults and nymphs suck the plant juices/sap, the leaves lose nutrients and water and become speckled, later turning yellow to brown. Under heavy feeding, plants begin to wilt, and the point of attack becomes black and brittle. Squash bugs may also feed on young fruits, causing scarring and death.

The adult and juvenile (nymphs) squash bugs can be found near the crown of the plant, underneath leaves, or hidden in the soil around the plants. When disturbed they move rather quickly. I have found that they tend to climb up on to the leaves when I am watering the plants to escape the deluge. This makes it easy to spot the adults and quickly dispose of them.

Unmated squash bugs find shelter in the fall under dead leaves, rocks, wood, and other garden debris to survive the winter months. In the spring, they fly from their protective habitat to nearby cucurbits where they feed, mate, and lay eggs.

Starting in the spring, to manage or help minimize the presence of squash bugs, look for squash bugs that may be hidden under debris, near buildings, and in perennial plants in or near the garden. Inspect young plants daily for signs of egg masses, mating adults, or wilting. Place wooden boards throughout the garden and check under them every morning, and then destroy any squash bugs found.

The UC Davis website says the best method for control is prevention through sanitation. Old cucurbit plants should be removed after harvesting is complete. Keep the garden free from debris that can provide overwintering sites for squash bugs. At the end of the gardening season, compost all vegetation or thoroughly till it under. Handpick or vacuum any bugs found under wooden boards. During the growing season, pick off and destroy egg masses as soon as you see them. Use protective covers such as plant cages or row covers in gardens where squash bugs have been a problem in the past and remove the covers at bloom to allow for pollination.

The UC Davis website also states that squash bugs are difficult to kill using insecticides because egg masses, nymphs, and bugs are often hidden and are difficult to reach with sprays. Several insecticides are available that are less toxic to the environment, which include products such as Neem oil, horticultural oil, and canola oil. These soaps and oils are most effective on the smallest nymphs, but good penetration throughout the plant's canopy is essential so that nymphs under the leaves and deep within plants will be covered. Other more toxic pesticides are also registered for use on squash bugs; however, these materials should be used with caution because of negative impacts on bees and beneficial insects such as predators and parasites that help to keep other pest insects and mites in check. In addition, they are not likely to give better control than handpicking combined with softer chemicals.

So far, I have had luck hand picking squash bugs as I find them since I do not seem to have and overwhelming population of them. My friend has had some luck controlling squash bugs with "Captain Jacks Deadbug Brew Flower and Vegetable Garden Dust," which is approved for organic gardening. There is a warning on the label, so care should be taken with this and all pesticides to ensure that damage does not happen to non-target organisms. It is the law to always follow the instructions on the label.