Green Grass in the Winter – Overseeding

front-yardGreen Grass in Winter

Late September to mid-October marks a major milestone for turf landscapes in the desert. At this time, those who want to maintain green parks and lawns through the winter need to overseed Bermuda grass with winter Ryegrass.

Bermuda grass, which grows well in the summer, turns brown and goes dormant with the first frost and remains that way until spring.  Ryegrass however, stays green and vibrant through the cooler months, with the exception of heavily shaded areas, and will die out with the return of triple-digit temperatures.

Steps for Overseeding Your Lawn

1. Timing is critical. The ideal time to overseed is when nighttime temperatures are regularly below 65 degrees (typically mid-October). About 2 weeks prior to overseeding, reduce the amount of irrigation water to the Bermuda by about half. This will signal the Bermuda to slow its growth and store energy for the winter.

2. In order to successfully spread the Ryegrass seed, you need to prepare the seedbed for planting. Lower the mowing height on your lawn mower in several passes, taking off about ¼ inch each mow cycle until the grass is approximately ¾ inch in height. Make sure to remove the clippings by mowing with a bag-catcher or by raking them up. The goal for this process is to make sure the Ryegrass seed comes into direct contact with the soil.

3. Now you are ready for seeding. For the best results, use perennial Ryegrass seed. Use a rotary spreader or drop spreader to evenly distribute the seed at a rate of 8 to 10 pounds per thousand square feet. To maximize germination, lightly rake and then cover the lawn with ¼ inch of mulch. Apply a starter fertilizer (6-20-20 or 6-24-24) after the seed is down. Water the area after spreading the Ryegrass seed, and set your irrigation clock to water 3 to 4 times a day at approximately 2 to 5 minute cycles. This schedule ensures the soil and mulch remain moist, and not overly wet, until germination. This step should take 7 to 10 days.

4. After the seedlings emerge, reduce watering to once daily. When the grass reaches about 2 inches in height, it is time for the first mow. Cut the grass to about 1½ inch in height and fertilize with a 21-7-14 fertilizer. Make sure to water immediately following the fertilizer application. Depending on temperatures and rainfall, you can then reduce the watering schedule to once every 2 or 3 days. To keep your lawn from turning yellow, fertilize every 3 to 6 weeks with ammonium nitrate (34-0-0) or calcium nitrate. Apply all fertilizers according to the directions on the package.

Hand Spreader

Use a rotary spreader to distribute seed.

By following these steps, you should achieve a lush, green lawn through the winter months and into spring. When triple-digit temperatures return, it will be time to transition from the Ryegrass back to the Bermuda grass.

Preparing for an Arizona Winter

Frost season in Phoenix typically runs mid-November through February. The frequency and intensity of frost varies in both rural and metro areas for a number of reasons including elevation and population density. Our cooler weather provides us with the opportunity to conserve one of the desert’s most precious resources; water.

Water Savings

From roughly Thanksgiving to the end of February, most desert and desert adapted plants do not require water. You can choose to reduce your watering schedule to just a day or two a week or even turn the controller off completely! If you choose to turn your controller off completely, it’s important to continually monitor your lawn for signs of stress and provide water when necessary  Once night time temperatures return to the upper 70s, you will want to start watering again. Since most plants go dormant during this time of year and you can find the emitter a little easier than when plants are blooming, late winter/early spring is an excellent time to check your irrigation system for any faults or malfunctions. Turn your controller on one zone at a time and verify that each irrigation head is functioning properly.

Protect your Backflow

When temperatures dip below 32 degrees Fahrenheit  your backflow is at risk for damage from freezing water that sits in the unit. Usually, the easiest way to protect your backflow preventer is to cover it with a towel or blanket, as pictured, on the nights that temperatures are projected to drop below freezing.  You can also choose to drain the water from your backflow if you are concerned about prolonged freezing temperatures or plan to be gone for several nights. For more information on how to winterize your home sprinkler system including your backflow, please visit the Colorado State University Extension website.

Frost Protection for your Plants

Cover plants susceptible to frost-damage with cloth towels, blankets, sheets or paper/cardboard boxes to insulate them. Plastic is not recommended for plant cover. Drape the paper or cloth all the way to the ground to help trap heat radiating from the ground under the cover. A nursery can help you identify material made specifically for covering plants. Remove the cover after sunrise each morning or when the temperature reaches 35 degrees.

Plants not native to the Southwest are most at risk for frost damage. These plants include Bougainvillea, Lantana, Winter Annuals and others. For cacti such as Mexican Fencepost, covering the tops of the posts with an old t-shirt, foam cup or wash cloth can help prevent frost damage. Watering plants the night before a frost can also help them stay warmer. Dehydrated plants are more susceptible to frost damage.

To Prune or Not to Prune?

If frost impacts your plant material, it is optimal to wait until the threat of frost has subsided to prune frost-damaged plants. Pruning away frost damage too early can result in additional damage to the plant if it is hit by frost again. New and un-established shrubs or ground cover plants are more susceptible to permanent damage and could be lost due to cold weather. Established plants with a sustainable root system can handle minimal pruning for aesthetic reasons throughout frost season.

When it comes to trees, some species like Ficus are particularly sensitive to frost damage. Many smaller trees may be lost all together and, unless particularly protected, significant portions of the larger trees may be severely damaged due to hard frosts. While it is hard to be patient, it is best to wait to see if new growth will come back. If you decide to prune the dead tissue, it will take years before it grows to its original size. If you decide to leave it, the green will eventually fill in, but you’ll be looking at brown dead tissue for several years.

No matter what steps you follow to prepare for cooler weather, it’s important to take proactive measures to prevent any loss of plant material, irrigation components and ultimately, your money, during the winter months.

For more information on desert landscape and plant care, check out Arizona Cooperative Extension. If you reside elsewhere in the southwest, contact your local Cooperative Extension office.

Turf Aeration

Beautiful, Healthy Turf

aerated turfTurf is an integral component of common area landscape. Its aesthetic qualities and value as a recreation surface make it a desirable part of many communities. Beautiful, healthy turf is always the goal in any maintenance plan, and this goal can only be attained with an intelligent approach to horticultural practices. Turf areas that are utilized frequently often suffer from soil compaction. Prolonged physical compaction of the soil results in a hard surface that does not allow efficient water penetration, oxygen absorption by the roots and movement of nutrients from the surface into the root system, which are needed for healthy turf. The effects of compaction can be mitigated by aeration, a valuable but often overlooked, horticultural practice that is a very effective tool for maintaining healthy turf.

Aeration Methods

Aerated TurfThe aeration process is achieved by different methods; all of them involve creating holes (3 to 6 inches deep) in the turf soil.  One common method of aeration involves forcing a solid tine into the soil through the use of gravity (weight), hydraulic down-pressure or vibration.  This is a fast, clean process in that no soil cores are removed and litter the turf.  Another method of aeration involves driving a hollow core tine into the soil and removing a small cylindrical-shaped soil “plug”.  These plugs are left on the turf surface and are broken up by subsequent mowing.  Golf course greens are aerated utilizing this method several times each summer.

The best time to apply soil amendments and fertilizer is immediately after aeration while the holes are fresh.  Amendments fill the holes and are quickly absorbed and distributed to the turf’s root zone.  Through aeration, water and oxygen penetrate the soil and roots and promote healthy turf. At home, apply a turf fertilizer after aeration to achieve the same nutrient balance in your soil.

Did You Know?

Compacted soils offer an ideal environment for a fungus known as Fairy Ring.

Fairy Ring

Dodder

IMG_6087Have you ever walked by a shrub that looked like it was covered with spaghetti? No, it’s not cloudy with a chance of meatballs – the plant is infected with a weed called Dodder. Dodder is a parasitic vine that is extremely difficult to eradicate. What is a parasitic vine? It’s a weed that depends on a host plant for all of its needs.

How to Identify Dodder

To spot Dodder, look for long, slender, thread like stems that kind of look like spaghetti. It may also have bell shaped flowers that are cream colored. Dodder is a tricky weed because it grows and branches out to nearby plants very easily. Because of this ability, it often looks like a matted mess covering up a whole plant. The more vines there are, the more energy that is removed from the host plant. The loss of nutrients to the Dodder combined with the loss of light from the matted weeds can cause major damage to the host plant.

IMG_6077Dodder Challenges

One of the biggest challenges with Dodder is its seeds. Dodder is a flowering plant and its flowers will produce thousands of seeds which, when mature, will fall to the soil below. The seeds have a very hard coat around them and stay dormant in the soil until the right conditions come around to sprout. When it comes to getting rid of a Dodder infestation, it is the seeds that cause the greatest headache, which is why prevention is so important.

Removal

At the first sign of Dodder, pull it off the plant and throw it away. Check the infestation site often because the weed may quickly regrow so it’s important to keep pulling. If you see Dodder soon after it has attached itself to a host, prune the infected portion of the host plant 1/8 to 1/4 inch below the point of the attachment, otherwise the dodder can regenerate. If the Dodder is attached to a shrub or tree, pruning is only helpful if it is confined to one or two branches. Removing any more than that will most likely cause major damage to the host shrub or tree.

Because Dodder is extremely difficult to destroy once it has taken over a plant, it is important to try to end the growth cycle. Use a pre-emergent herbicide like oryzaline that, when added to the soil under the infested plants, will kill the seed before it grows. Currently, there are no post-emergent herbicides that kill dodder without also killing the host plant. If the infestation is completely unmanageable, removal of the host plant with its attached dodder may be the easiest solution.

From The Case Files: Agave Snout Weevil

Agave Weevils LCWhat Are Agave Snout Weevils?
Agave Snout Weevils are inch-long, dusty black, wingless insects and — as their name suggests — are particularly fond of Agave. Adults are known to lay their eggs between the leaves of Agaves, and the hatching larvae burrow into the plant. Infestation causes Agaves to collapse into a rotting mess during late summer and early fall.

How Do I Know If My Agave Is Infested?
Agaves 1 LCTypically, an Agave Snout Weevil infestation is not discovered until the damage is too severe to save the plant. As the insects feed on the plant, they inject a bacterial infection, causing the leaves begin to wrinkle. The leaves will continue to shrivel over time as the infection moves through the heart of the plant. You might also notice a foul odor as the plant rots. The Agave will eventually collapse, leaving only the central spikes of the plant still standing. By this point, rehabilitating the plant is unlikely.

Agaves 2 LCHow Do I Eradicate Them?
Once you’ve recognized that you have an Agave Snout Weevil problem, it’s important that you remove all dead and infected plant parts from your garden. DLC’s Experts recommend inspecting the surrounding soil for adult weevils or larvae. Any remaining adults or larvae must be removed to avoid the infestation of other plants.

The key to eradicating Agave Snout Weevils is proactive prevention. Once the pests have infected your Agave, it’s nearly impossible to reverse the damage. The best thing you can do is prevent future attacks from claiming the lives of other plants. DLC’s Experts suggest applying a pesticide with Imidacloprid as the main ingredient around the base of the plant in early April and again in late May. Imidacloprid is a systemic insecticide so it will work its way from the base through the entire plant and keep Agave Snout Weevils from feeding on it. Pesticides containing Imidacloprid can be found at your local home improvement store or nursery. As with any pesticide, follow the instructions on the label for proper use.

Monsoon Season: Ready or Not Here It Comes!

With summer temperatures creeping into the triple digits, Monsoon Season is just around the corner. Summer monsoon storms offer much needed rain to our desert environment, but also pose the biggest weather related risk for trees. If not pruned and thinned properly, your trees are more likely to become the victim of high monsoon winds.

Now is the time to assess your trees to determine if they are in need of pruning before the monsoon storms arrive. If you didn´t prune your trees in the cooler months, it is prudent to do the work before the storms arrive. In preparation for monsoon winds, the tree´s canopy should be thinned so wind can pass through the tree easier. Typically, most pruning involves lifting a tree´s branches to a height that people can walk under. When monsoon winds arrive, the tree´s canopy is top heavy because the weight of the trees is concentrated above a certain height. Assess your trees in the upcoming weeks and remove overly thick foliage, correct damage from previous storms and remove dead or structurally unsound branches to minimize the chance the tree will be damaged or cause damage during a storm.

Having proper tools to prune your tree is important to the health of the plant material. Limbs up to 1/2 inch in diameter can be pruned with hand pruners. Long-handled pruning loppers can handle limbs up to 1 inch in diameter but a special pruning saw is needed for larger limbs. Hedging shears or power hedge trimmers should not be used to prune trees because they will not be able to make proper cuts and will damage the tree.

Before and AfterIn spite of the damage these summer storms can cause, there is a silver lining to the monsoon clouds: moisture! The monsoon presents us all with a great opportunity to save water. We assess the amount of water each storm brings and suspend or adjust irrigation schedules appropriately. Not only is rainwater free, it is also superior to irrigation water due to its lower alkalinity. In addition to providing moisture, the rainwater helps leach accumulated salts away from the roots of shrubs, trees and turf.

Following a storm, check the status of your irrigation controller. Power outages can reset irrigation clocks and schedules, and it may not be appropriate for the weather. If your property receives a substantial amount of rain, turn off your irrigation system. Be aware of your plant material and soil moisture in order to determine when the water needs to be turned on again. Overall, you may not need to water as much as you did in the drier months.

Planting and Caring for New Plants

Whether you want to add new plants to your yard or you’re replacing plants you lost to winter’s freezing temperatures, now is the time to plant to give them the best chance of surviving the summer heat.

Shrub and Tree LandscapeIdeally, new plants should be installed when nighttime temperatures are over 55 degrees for a prolonged period of time and daytime temperatures are less than 90 degrees. For our desert landscape, plant replacement is most successful in the early spring because temperatures and humidity allow the plant to establish itself in its new environment before the harsher summer weather arrives. Certain tree species like acacia salicina and the desert willow demand spring planting because they establish new roots very slowly.

When choosing your new plants and trees, ask yourself these following questions:

Is it the right plant/tree for the right space?

How big is your plant or tree going to be in its mature size as it relates to its space? Does it have thorns that could grow into the common areas and sidewalks?  Do the roots have enough space to find the nutrients it needs? Expect trees to have root systems that reach out underground has far as its canopy extends.

What kind of light does it need?

The closer that the plant is to those hard surfaces like sidewalks and brick walls, the more sun and heat it will absorb. Be cautious of placing plants near these reflective surfaces.

How much water does it need?

Young plants will need more water as they root out looking for nutrients in the soil. Look for signs of distress like wilting or curling of leaves, leaves losing their color, and dead stems as signals of needing to water more. Also consider possibly using mulch or fertilizer to boost the young plant’s growth.

A young tree will need to have more emitters located near its trunk initially. These emitters will need to be moved from the trunk on a yearly basis to encourage the spread of the roots as the tree matures.