When to Plant? That is the Question

When to Plant.jpg

Even if it is too early to plant, it’s never too early to start planning your garden. Learn from USU Extension gardening expert Taun Beddes when you can safely plant your vegetable garden.

One day it is sunny and warm, and the next day it is raining and cold. Or in northern Utah, it could even be snowing.

Determining when to plant a garden can be especially confusing in Utah’s unpredictable, varied climate where last-frost dates can vary by many days within just a few miles. Many experienced gardeners have planted and later lost their plants to frost.

As you determine when you should plant, consider the geographic characteristics of where you live. When a yard is located in a populated area or on a mountain bench, it usually has a longer growing season. Other areas located at slightly lower elevations where cold air drains and cannot escape have a shorter season. This is why local commercial orchards are generally located on benches. Additionally, urban and suburban areas are slightly warmer than surrounding areas due to the urban heat effect. Heat from buildings and warmth generated by sunlight reflected from roads and other surfaces increases temperatures and delays frost. It can be helpful to chat with a local farmer or experienced gardener in your area to determine what works for him or her regarding when to plant.

In addition to frost information, it is important to take into account the needs of the plants. Vegetables planted locally fall into four basic categories: hardy, semi-hardy, tender and very tender. Depending on which category a plant belongs to, planting dates vary from early spring until early summer. Consider the following:

  • Hardy vegetables, including asparagus, broccoli, cabbage, onions, peas and spinach, can be planted as soon as the soil is workable in early spring. This usually ranges between 45 and 60 days before the average last frost. These same vegetables can be safely planted until the average last frost date.
  • Semi-hardy plants, such as beets, carrots, lettuce and potatoes, can be planted one to two weeks after the hardy group. These can be planted until the average last-frost date.
  • Tender vegetables, such as celery, cucumbers, corn and most beans, should be planted on the average last-frost date.
  • Very tender plants, such as squash, beans, melons, tomatoes, eggplants and peppers, should not be planted until at least a week after the average last frost. Even if frost does not occur before this time, these plants will not grow well and are more susceptible to disease until warmer weather.

If you have lost plants to frost, you are not alone, and all you can do is try again.

Average Frost Dates for Various Utah Locations (Note that these dates are averages and can vary from year to year.)
        Frost Dates
City Last First Frost-Free Days
Alpine May 20 September 30 136
Blanding May 13 October 12 153
Cedar City May 10 October 5 148
Delta May 17 September 28 134
Farmington May 5 October 10 158
Fillmore May 16 October 4 140
Huntsville June 11 September 9  89
Kanab May 7 October 20 166
Lake Town June 15 September 10  87
Logan May 14 September 25 135
Morgan June 6 September 11 98
Moroni June 1 September 18 109
Ogden May 1 October 24 176
Park City June 9 September 1  92
Price May 12 October 7 148
Roosevelt May 18 September 25 130
Spanish Fork May 1 October 13 165
St. George April 6 October 28 205
Tooele May 7 October 14 159
Tremonton May 3 October 10 160

This article was written by Taun Beddes, Utah State University Extension horticulturist, 801-851-8460, taun.beddes@usu.edu

Ask a Expert // How Can I Keep My Landscape Looking Lovely in the Heat?

Landscape in the Heat.jpgThe heat is on, and many lawns are struggling. Consider these suggestions for keeping your landscapes and gardens healthy while also saving water.

Go easy on the watering.

In almost all circumstances, plants tolerate or prefer to have variations in soil moisture. This means that it is perfectly fine for soil to dry out moderately between irrigations. Soil that is kept overly wet reduces vigor and can actually harm plants.

Watch for the signs before watering.

Do not rely on a sprinkler clock or irrigation controller to irrigate lawns on a set schedule. Instead, determine when the lawn actually requires irrigation and manually activate the system as needed. A common sign of drought stress in turfgrass is grass blades not quickly springing back upright when walked on, leaving a trail of footprints in the lawn. Additionally, walking on a lawn barefoot can let you feel how dry the soil is. Relatively dry soil under the grass is hard, does not “give” when stepped on and is slightly uncomfortable to walk on. Wetter soil depresses a bit when weight is applied.

Choose the right time to water.

Do not water between 10 a.m. and 6 p.m. During this period, up to 50 percent of water emitted from sprinklers is lost to evaporation. Instead, irrigate when the sun is down or low in the sky.


Spot-treat brown spots.

Small areas of the lawn can brown during hot weather because of variations and inefficiencies in sprinkling systems. Instead of increasing the amount of time the entire sprinkling system irrigates, supplement water to the brown areas with a small hose-end lawn sprinkler or water by hand with a hose.


Don’t cut the lawn too short.

Mow the lawn to a height of at least 2 inches. This allows roots to penetrate deeper into the soil and increases overall drought hardiness.


Go deep.

When irrigating turf, water long enough for the water to penetrate 6 to 12 inches into the soil. This encourages deeper root development and reduces the frequency of required irrigations.


Adjust watering based on sun exposure.

Irrigate shady and sunny areas according to need. Shady areas require much less irrigation than sunnier areas.


Mulch your beds.

Cover bare soil in the garden and flower beds with 2-3 inches of mulch. Not only does this save water, it greatly reduces the need for weeding. Inexpensive mulch can be obtained from many local green waste recycling centers. Grass clippings also work well and are free.


Hand water or use drip irrigation for flower and garden beds.

Hand-water or use drip irrigation to irrigate flowerbeds, vegetable gardens and shrub beds. Water should be placed near plants and penetrate the soil 6 inches deep for flowers and veggies, and 2 feet into the soil for established trees and shrubs.

This information was provided by Kelly Kopp, Utah State University Extension water conservation and turfgrass specialist, 435-757 6650, kelly.kopp@usu.edu and Taun Beddes, USU Extension horticulturist, 801-851 8460, taun.beddes@usu.edu

Ask an Expert // Five Fall Must-Do Yard Tasks


With autumn here, it’s time to think about getting the yard ready for winter. Consider the following tasks that will help your yard be healthy and happy next spring.


  1. Remove leaves by raking, mowing or vacuuming with a leaf blower. Mowing and vacuuming chop up leaves and reduce the bulk so more fits into leaf bags or compost piles. The reduced bulk also makes it easier to mix leaves into the soil. Do not send them to the landfill, as they are valuable for improving the soil and easy to compost. Instead, send them to green waste or check with neighbors who might be able to use them.
  1. Early to mid-fall is a great time to spray lawn weeds such as dandelions and harder-to-kill perennial weeds such as field bindweed (morning glory). There are many products that are registered for spraying on the lawn, but if you need to spray in the garden, avoid contamination by making sure all produce is removed and you are done for the year. As always, read and follow all product labels.
  1. Just after the first hard frost is the best time to cut back annuals and perennials. Foliage will be scorched and yellow or brown. Cut perennials a few inches above the ground and do the same with annuals, or pull them out completely. If the removed foliage is not diseased, compost it or send it to green waste. If it is diseased, throw it away. This is also a good time to apply 1-3 inches of compost to flowerbeds. If there is risk of damage to existing plant roots, the compost does not need to be tilled in.
  1. The final lawn mowing should occur between late October and early November. Lower the mowing height to around 2 inches. This helps slow the spread of winter-active fungal diseases such as snow mold. It is also important to remove all leaf litter from the lawn.
  1. If the lawn had moderate-to-heavy traffic during the summer, fall is a great time to fertilize. The lawn stores nutrients and will break dormancy sooner in the spring. There are many standard and organic fertilizer options available. Follow the instructions on the bag.


One thing you should not do in the fall is heavy pruning of woody plants. Pruning delays dormancy and can make these much more susceptible to winter damage. Instead, between mid and late winter is a much better time to prune ornamental trees. Prune most flowering and fruit-bearing trees in late winter or early spring. If shrubs do not flower or they flower in the summer, prune in late winter. Spring flowering shrubs such as snowball bush, bridal wreath, lilac, etc., should be pruned as soon as they are done blooming in the spring.

This article was written by Taun Beddes, Utah State University Extension horticulturist, 801-851-8460, taun.beddes@usu.edu

Ask an Expert // Fall Planting Brings Winter Color


Take advantage of fall plant sales and add some winter color to your landscape with these suggested varieties.

Most nurseries and garden centers are holding fall sales to reduce plant inventory. The timing is right, because with cooler temperatures, now is a great time to plant. Many plants are available that will help create winter interest in the yard. Consider these varieties for a splash of color in the upcoming months.

Lavalle hawthorn: This beautiful and durable tree grows well in most populated areas of Utah. It has white spring flowers and dark green summer leaves. The leaves often turn brilliant red in late fall and stay on the tree until December. The fruit is also red and stays on the tree most of the winter, serving as a meal for cedar wax wings and other birds. This tree can have thorns, but they do not generally cause problems.

 Red and yellow twig dogwood: These shrubs thrive in wetter areas of the yard and grow 6 to 12 feet tall and wide. There are many varieties with beautiful coral-red bark, along with a few that are bright yellow. The branches are often used to make wreaths. Heavy spring pruning keeps the size in check and encourages new growth that has the best color.

Holly: Not many holly species perform well in Utah. However, in protected areas, the blue holly series is an exception. These hold their leaves throughout the winter and have the classic holly foliage popular during the Christmas season. These are best grown where they receive afternoon shade. If berries are desired, a male and female cultivar must be grown, such as Blue Prince and Blue Princess. There are many other broadleaf evergreens that can grow in protected areas. They include English laurel, boxwood and Japanese euonymus. They also need afternoon shade and are often browsed by deer.

 Crabapples: There are dozens of crabapple varieties available; all with beautiful spring flowers. Unfortunately, they have received an often undeserved reputation as being overly messy. Many new types have fruit in lovely tones of red and yellow. The fruit stays on the tree (referred to as persistent fruit), unlike older varieties, which creates winter habitat for many kinds of birds. Some varieties to consider include Indian Magic, Prairie Fire, Royal Raindrops, Profusion and Snow Drift.

 Late winter blooming plants: There are actually a few plants that bloom before forsythia, an early bloomer. These include common winter hazel and hellebore. Common winter hazel is rare in Utah, but seems to do well in slightly protected areas. It grows to the same size as a lilac and has delicate, light-yellow flowers. Hellebores are also known as Lenten rose because they start blooming around the same time as the Catholic Lent and continue throughout the spring. They are a perennial and spread a few feet wide per plant.

This article was written by Taun Beddes, Utah State University Extension horticulturist, 801-851-8460, taun.beddes@usu.edu

Ask an Expert // Four Tips for Dealing with Problem Soil

Problem Soil

The condition of the soil often dictates success or failure in the landscape. Before spending money on trees and plants, be sure your soil is suitable for planting. 


Consider these tips for dealing with four common soil problems.


1. Rocky soil: 

Rocky soil is usually fine for growing plants, but rocks make digging or cultivating difficult. It is better to get rid of surface rocks where turf and garden areas will be. Be innovative with the removed rock. Are there areas where rock mulch can be used to suppress weeds and conserve water? Will retaining walls be built? In the worst situations, it may be necessary to garden in raised beds or to bring in topsoil. If topsoil is used, add a minimum of 6 inches.

2. Soil is too hard to dig:

During the summer, it is common for soil to become too hard to dig or cultivate. This is difficult for new homeowners without an irrigation system who are trying to create a landscape. In many areas, secondary irrigation water is stubbed into the yard. Try installing a temporary hose bib into the stubbed secondary water. This allows a hose-end sprinkler or drip hose to be used to moisten the soil and make it more amenable to digging or cultivating. If this is not possible or if secondary water is not available, prudent use of culinary water may be needed to moisten the soil.

3. Clay soil: 

Those with clay soil often have difficulty getting water to penetrate the soil without it running off. If possible, amend with 2-3 inches of quality compost (not peat moss) 6 inches deep before planting. This will break it up and begin the process of creating quality topsoil. It may take 5-10 years of doing this before noticing improved soil quality. One irrigation management technique is to break irrigation events into segments spread out over a few hours to allow water to better penetrate the soil. When fertilizing turf, make half applications twice as often to avoid runoff of the nutrients. If other options haven’t worked, it may be best to use raised-bed gardening.

4. Compacted soil:

Excessive foot or vehicle traffic can compact soil. This destroys soil structure and does not allow water to penetrate. More frequent hollow tine aeration can help with minor to moderate compacted soil. In extreme situations, soil ripping is needed. If the soil is ripped or if the problem can be alleviated before planting, start by incorporating 2-3 inches of quality compost as deeply as possible. If the area continues to see heavy traffic, install pavers or flagstone to alleviate re-compacting the soil.


Soil testing is a helpful way to learn about specific soil characteristics and prevent potential problems. The Utah State University Analytical Laboratory offers soil analysis. A routine test gives phosphorus and potassium levels; pH; salinity and the soil texture (clay, sand, silt, loam, etc.). Visit http://www.usual.usu.edu/ for more information.

This article was written by Taun Beddes, Utah State University Extension horticulturist, 801-851-8460, taun.beddes@usu.edu.

Ask an Expert // Four Tips for Getting Rid of Eerie Earwigs

Eerie EarwigsEarwigs can be creepy, and while they don’t actually crawl in your ear, they can cause some serious damage to the plants in your garden. Learn how to keep them at bay with these four expert tips.

European earwigs are common in Utah and are easily recognized by the large pincers on the end of their bodies. The ideas that earwigs crawl into ears and that their pincers are dangerous are both false.

Earwigs are active at night and often go unnoticed; however, holes chewed in leaves can indicate earwigs have been dining there. If you suspect that earwigs may be eating your plants, examine them at night with a flashlight. Earwigs can be beneficial, acting as decomposers and predators of insect pests such as aphids and scales. However, they also feed on many vegetables, leafy greens, flowers and a wide variety of fruit. Since they spend the winter as adults, they can also become an indoor nuisance pest. Consider these tips for ridding your home and yard of earwigs.


1.)  Homemade traps are inexpensive and can reduce earwig numbers in specific areas. One type is made from corrugated cardboard. Cut a 6-inch-wide strip of cardboard and roll until it reaches about 4 or 5 inches in diameter. Tie the roll with string to keep it intact, then tie it to the lower trunk of a tree. Collect the cardboard traps every two or three days, seal the earwigs inside a bag and throw the earwigs and the trap away. Rubbing the cardboard with fish oil or bacon grease can make the trap more effective.


2.)  Another type of trap is a sour cream, cottage cheese or margarine container with strong-smelling oil, such as fish oil or bacon grease, poured into the bottom. Bury the container in the ground almost to soil level, and cut a small hole in the lid for the earwigs to enter. The containers can be collected every few days and reused after the earwigs are dumped into a bag and sealed.


3.)  Commercial, non-chemical control products are widely available, such as diatomaceous earth. This product is not harmful to pets or humans, but works by cutting or absorbing the thin, waxy layer that covers insects. Sprinkle it around the base of plants that earwigs and other insect pests, such as aphids, scales and caterpillars, are damaging. Be aware that once diatomaceous earth contacts water, it becomes ineffective. It must be reapplied after rain or watering. To keep earwigs out of fruit trees, try wrapping sticky traps, such as Tangle Guard, around the tree trunk.


4.)  Occasionally, it may become necessary to spray an insecticide to effectively control earwigs. Organic and reduced-risk products are available such as pyrethrins and spinosad. Pyrethrins are derived from a species of chrysanthemum and control many insects. Spinosad is derived from a bacterium harmful to many insects but not mammals. Both are often labeled for use on many vegetables and fruits. Other chemical sprays are effective, but may harm natural enemies of earwigs and other beneficial insects. Of these available to homeowners, carbaryl (Sevin), malathion and permethrin are commonly used. Using non-chemical methods before resorting to sprays is recommend in most non-commercial situations.


A video about making homemade traps is available at https://youtu.be/tlgpfCT0wYo.

This article was written by Taun Beddes, Utah State University Extension horticulturist, taun.beddes@usu.edu. Ryan Davis, USU Plant Pest Diagnostic Lab insect diagnostician, contributed to this column.

Ask an Expert: How to Keep Your Aspen Trees Happy

Aspen Trees Graphic - Copy

Have you ever wondered why your aspen trees are sprouting volunteers in your lawn, or have you wondered how to keep the mature trees from dying off? Check out these answers and tips from USU Extension horticulturist Taun Beddes.

In the wild, aspen are among the most beautiful trees with their almost snow-white trunks, shimmering leaves and yellow fall color. Because of these qualities, many homeowners have planted them, but have then watched mature trees die quickly. Unfortunately, aspens often struggle and are short lived, living anywhere from 5 to 15 years when outside their native habitat. When planted around homes, they are more susceptible to insect/disease problems and nutrient deficiencies from stress caused from being away from their native habitat. Consider these tips for aspen care.

Contain Root Suckers

Aspens form surface roots and primarily propagate by sending out root suckers that form new trees connected to the mother plant. Both of these qualities make mowing around them difficult. Fortunately, aspens do not usually grow large enough to damage foundations or cement, due to their short lifespan. One possible solution to contain roots is to surround the rootball of newly planted trees with a cement or rust-proof metal ring 3 to 4 feet beyond the root system and about 2 feet deep. Another is the use of products such as Sucker Stopper that are sprayed on newly cut suckers. They are intended to slow or prevent sucker formation from the spot where it is sprayed. This control method is not perfect, however, and is only good for one season. The spray can cost $20 to $60 per bottle, depending on the concentration.

Try Columnar Swedish Aspen

Columnar Swedish aspen is similar to our native species but taller and narrower when mature. It is relatively new to the landscape and seems to send fewer root suckers. However, it is still susceptible to pests and diseases like the native aspen and can decline rather quickly.

Location, Location, Location

Even with the limitations aspen have, they can still be used in moderation in the landscape if managed properly. It is important to plant trees in a location where suckering will not be a problem such as landscape beds that are well away from turf areas. Aspens can be enjoyed as long as they are healthy and then cut down when they begin to decline. Younger trees, formed by root suckers, will quickly mature and sustain the stand. These trees should be watered to a depth of 2 feet every 2 to 4 weeks. It is not recommended that trees be overly treated with chemicals when problems occur regularly. Homeowners can easily spend more money on pesticides than the purchase price of a replacement tree.

Other Options

Trees to consider as replacements for aspen include chanticleer/Cleveland pear, Queen Elizabeth maple, Tatarian maple, black alder, various crabapples and Sargent cherry. These trees don’t look exactly like aspens but have their own ornamental qualities, are usually much less susceptible to pests and diseases and are much longer lived

This article was written by Taun Beddes, Utah State University Extension horticulturist