Author: ptillman

July 8, 2017 ptillman



I just moved Redding, California and I want to know if I can grow citrus trees?




A  There are several microclimates in the Redding area where citrus do very well with little need for frost protection.  But the seasonal temperature highs and lows in your area may dictate if the citrus survives or thrives. The optimum temperature range for citrus growth falls between 70°F and 90°F. Most citrus growth stalls when lower than 55°F, or when above 100°F, and some varieties also won’t ripen their fruit when temperatures rise above 100°F. Generally speaking, citron, lemons, and limes are particularly susceptible to frost damage. Grapefruit, mandarins, and oranges have a medium sensitivity to frost damage. Kumquats and Satsuma mandarins can be quite frost hardy.


 Citrus can be grown outside in USDA Hardiness Zones 8-9 with frost protection such as insulating the trunks with fiberglass, cardboard, or an old blanket stacked up to the main branches. Wrapping the insulation layer with plastic will also aid in keeping it dry during rain, but plastic alone will not protect the trees from frost.  Microclimates can be created in the yard by placing trees in a protected area, such as close to the wall of the house, to prevent frost damage. Few citrus appreciate high winds, but good air circulation can help prevent frost damage, minimize pests, and diseases.


Mulches are valuable during the warm months for conserving soil moisture and keeping the roots cool, but during the cold months mulches actually prevent the radiant heat of the soil from protecting the citrus tree trunks. Scraping the mulch back from within the drip line and keeping the soil evenly moist during frost warnings will help protect the trunk and the roots from frost damage. Additional frost protection can be obtained by placing a 100 watt light in the interior of the tree, as will using a string of old fashioned holiday lights wrapped around the tree. [Note: LED lights give off no heat and will not prevent frost damage].  Citrus need to be fertilized to produce fruit but timing fertilizer applications is also important especially if you are living in an area prone to winter frosts. Fertilizing stimulates tender new growth in citrus, but if it is done too late in the summer an early frost can damage the tender leaves. Citrus fertilization is best done no later than August to allow foliage time to harden off before frosts. Citrus are quite varied in their bottom line temperature tolerances before they succumb, but even those who live in the cold Zone 7 can grow citrus in pots that  can moved indoors, to an enclosed atrium or patio, or perhaps in a well-lit garage to spend the winter.

July 8, 2017 ptillman



What are some things to do for winter gardening?



It may seem like yardwork is slowing down now that most of the leaves have fallen and the grass is growing slower but now is the time to take advantage of winter dormancy. This is the time to move plants, plant bare root plants and do the majority of your pruning.


 From December through late February local nurseries will have bare-root plants. These are plants that are dug while they are dormant, and are sold with their roots exposed. Often they are more affordable than containerized plants, and they are definitely easier to handle. You’ll find fruit trees, cane berries, asparagus, artichoke crowns, rhubarb, kiwi, strawberries, grapes, roses and vines available as bare-root plants.  If you are stressed with holiday activities, getting out in the garden and planting can help get you in a better frame of mind.  If you are short of time, ask the nursery to hold the plants until after the first of the year. This gives you an opportunity to prepare the planting hole when the ground is pliable but not soggy and to enjoy the planting process.


 January is also time for winter pruning, make sure to space your tasks between rains so that pruning cuts have a chance dry out.  Wait to prune your apricot trees until mid-summer when there is no chance of rain for weeks. This prevents Eutypa dieback that commonly kills branches or whole apricot trees.

This time of year is also a good time to prune back ornamental grasses and perennials that were not cut back in fall.  And it is the best time to prune out the old canes from cane berries such as raspberries and blackberries.  If you plan to move a plant or dig it up and divide it, January and early February are the best times for this.


Another winter chore is treat fruit trees with dormant sprays.  Apply a horticultural oil to control scale, mites, aphids, and other insects and a copper based spray to control leaf curl in peaches and nectarines. Once again, check the weather and make certain that there is at least 24 hours of dry weather and around the application.  When spraying the tree with dormant sprays make sure that you follow label directions and wet the entire tree until the branches are dripping.

July 8, 2017 ptillman


A caller to the Master Gardener office would like to know how to take care of Lion’s Ear (Leonotis leonurus), after it has finished blooming?  Should it be cut back? And if so, when should they cut it back?



Leonotis leonurus is a beautiful broadleaf evergreen large perennial with orange flowers native to South Africa. It also known as lion’s tail and wild dagga, and is a plant species in the Lamiaceae family. It appreciates well-drained, loamy soil with plenty of compost.  It is drought tolerant and can take full sun.   Lion’s Ear can typically survive temperatures down to 20 degrees F but may freeze back and come back from the roots in the spring when exposed to temperatures in the low 20s.

If you don’t like the look of faded flowers, you can cut the flower stems back by about half in the fall.  Otherwise, you can leave them until late winter or early spring and then cut back.


In a cold winter, the plant may freeze and the foliage will turn brown.  Wait until late winter to cut the dead vegetation down, just above live growth.  Cover the roots with a 1-inch thick layer of mulch.   Mulch the roots, but don’t cover the crown of the plant.  Covering the crown could cause the plant to rot.  The plant should resprout with new growth from “hardened wood” in the spring.

During a warmer winter, the plant may remain green all winter.  However, in order to stimulate new growth for the next season, cut the plant by about half in the early spring.


The Shasta Master Gardener Program can be reached by phone (530) 242-2219 or email The Gardener office is staffed by volunteers trained by the University of California to answer gardener’s questions using information based on scientific research.

July 8, 2017 ptillman


I would like to give my friend a house plant as a hostess gift but she has cats so I don’t want to give her one that is poisonous.  Can you recommend a houseplant to give her?




Houseplants are a wonderful gift, not only do they help beautify the house but they help cleanse the air!  NASA was the first to experiment with detoxifying the air with plants. While some plants filter benzene from the air, others filter formaldehyde and other household toxins. The University of Minnesota says that it takes approximately 15 (8- inch pot size) plants to clean the air in a 1800 sq ft house.


 Unfortunately most of the plants listed as the best at filtering the air are also toxic to cats. However all houseplants will filter the air and brighten our mood while doing so.  The Gold Fish plant, Spider Plant, all Peperomias and most of the small palms are easy to grow and non-toxic to cats. They take moderate light and fits into many decorating schemes. Other house plants that are a bit harder to grow but that are cat safe are the Prayer Plant, the Phalaenopsis Orchid, the Polka Dot plant and many of the Begonias.  These plants like bright filtered light, may require special watering practices and warmer house temperatures at night. 


With all houseplants avoid placing them in trouble spots, such as near heat or air conditioning ducts, on electronics or a radiator or between a curtain and a frosty window. Remember that air conditions can be very dry in the winter because of heated air. You can provide a little extra humidity with a pebble tray and some misting.


House plants should only be fertilized every other month with a good houseplant fertilizer and allowed to rest without fertilizer during the winter months.  They should also not be overwatered, and at least once a month should be put under the shower spray to flush accumulated salts out of the pot and rinse dust of the leaves. 


There are many studies to prove that plants make us feel happy. They brighten our environment, make oxygen from CO2 and filter our air. During the short winter days when many folks are feeling depressed a plant will help to cheer them up.  As you are thinking of the perfect Christmas gift, why not give a plant?


For more information on house plants that are safe for pets, both cats and dogs, check out the ASPCA’s website.

July 8, 2017 ptillman



I want to order some seeds for my garden but am confused by some of the information.  What is the difference between an Open Pollinated seed and a Hybrid?  I am new to gardening, growing my first garden last year, and want to make sure that I don’t make mistakes with seed choices.


You are wise to ask for more information as choosing the wrong seed can be both disappointing and expensive.  For long time gardeners, choosing and ordering seeds is a fairly straightforward activity, but for those who are not quite as experienced it can be rather confusing.  There are a lot of different seed companies, all with wonderful and delicious sounding descriptions and photos. 

Hybrid seeds are often denoted as F1 and are derived from two or more different plants with traits that improve on the best characteristics of the parent plants. Such as better yields or disease resistance. Hybrid Tomato seed descriptions will often include letters following their name such as (AB, V,F,N) showing the  disease resistance of that verity. However if you plan to save seeds, savings seeds from hybrids will not guarantee the same plant in future plantings. Open Pollinated (OP) seeds are those that will produce plants genetically identical to the parent plant when seeds are saved for future plantings because they will breed “true.” Heirloom seeds are open pollinated varieties that have been passed down through the generations for 50 years or more, and may have distinctive colors, shapes and flavor. However, heirloom plants may not always have the benefit of resistance to diseases as their hybrid counterparts do.

Both types of these seeds can be listed as organic or treated.  Organic seeds (O) have been harvested from plants grown organically without the use of synthetic fertilizers or pesticides. Treated seeds are seeds that have been coated with something.  This can be a fungicide or insecticide to increase a seed’s ability to sprout without rotting or being attacked by insects in the soil or in the case of peas or beans it maybe natural beneficial bacteria to encourage better growth. Many seed companies add color to the treatment to set them apart from untreated seeds. An example of this would be yellow corn seeds appearing pink.

Since tomatoes are usually at the top of the list for seed ordering, the descriptions of various types would include the terms determinate or indeterminate. Determinate tomato varieties have fruits that ripen at the same time and have a bush-like habit. They usually do not need to be supported by staking or caging. Many gardeners have better luck getting a crop from these type of tomatoes as they are not dependent on weather conditions to set fruit.  Indeterminate tomato plants on the other hand ripen throughout the growing season and continue to grow right up until the first frost. These do need staking, caging or trellising for support.  Many of these verities may wait until late September to start setting fruit if we have to hot a summer temperatures.

Here are a few other things to keep in mind when choosing seed:

Consider buying seed from one of our local small nurseries as they try to carry seed that does well in our local area.

If ordering from a catalog, order early. You will avoid the disappointment of requesting a sold out item and you may even be rewarded with a free bonus seed packet if you get your order in early. Pictures in seed catalogs can be sometimes deceiving and a variety of plant that you “just have to have” may not be suited to our local climate.  Look for terms like “heat tolerant” or “wide adaptability” that will indicate the plant will tolerate the heat and large temperature swings between night and daytime.

If you have friends or neighbors who are gardeners ask them what verities have done will for them, this will help you avoid ordering something that will not do well in your area.

April 24, 2017 ptillman

logomakr_2uwedb  QUESTION:  

Can you recommend some plants that I can easily grow for their edible flowers?


 Edible flowers can be fun and easy to grow and they are often very ornamental so they can serve double duty.  You can use them in the landscape or as cut flower to decorate the table as well as adding them to your plate.  Using flowers for culinary purposes was very popular during the Victorian era. Cookbooks from that time contain recipes for salads and soups flavored by many different flowers. Today, serving edible flowers is a popular way to impress your friends and family. For food safety purposes do make sure you know where the flowers have come from. Avoid commercially-grown flowers. These flowers may have been sprayed with pesticides that are carcinogenic.


Here are some easy to grow flowers that are wildly recognized as safe to ingest:


Nasturtium (Tropaeolum majus): use Nasturtiums in salads, sandwiches, omelets and soups. Their brilliant bright-colored blossoms are edible and have a peppery taste similar to watercress. They thrive in full to slightly filtered sun, and grow easily from seed.  They may suffer in the heat of summer so are best grown in the spring or fall before or after danger of hard frost.


Borage (Borago officinalis): the delicate, star-shaped flowers are a clear blue and have a cucumber taste. Borage blossoms can be used to garnish lemonade, sorbet or a gin and tonic and are easily frozen in an ice tray. Borage will self-sow for years. These plants do best in full sun.


Calendula (Calendula officinalis): Calendula’s yellow or orange flowers look lovely tossed onto the top of a salad or decorating a cake. Dried petals can be stirred into soups, pasta, and rice dishes as a home grown substitute for saffron. Calendulas should be planted in fall or early spring and do best in full sun and are easy to grow from seed.


Lavender (Lavandula angustifolia): this fragrant small shrub has flower that brings are used to make wands and sachets. The purple flowers can be used to flavor jams and jellies, stews, or vinegar or used in a tea to calm the nerves. Easy to grow in a dry, well drained, sunny location.


Bee Balm (Monarda didyma): easy to grow, low maintenance, and drought-tolerant once established. This perennial sparkles in the summer with shaggy heads of tight tubular scarlet, pink or purple blossoms. The flowers can be scattered on salads, used as a garnish, or steeped to make Bee Balm teas. Bee Balm flowers have a citrusy flavor.


Johnny-jump-up (Viola tricolor): this flower blooms profusely in the fall and spring with little care in sun or shade and self-sows. It has small yellow, white and purple flowers (thus the name tricolor). Flower shave a slight wintergreen flavor. They make a pretty decoration for salads and desserts or in a punchbowl. A prized edible that can also be candied or frozen in ice cubes.


The best time to harvest flowers is in the morning if possible. Wash them quickly in cool water, shake them out, and dry them on a paper towel. If you won’t be eating them right away, store them between damp layers of paper towels in the refrigerator. Flowers are very fragile, and best added to the plate at the very last minute so that they don’t wilt. Fresh flowers can lend color and a festive atmosphere to food, but not just any flowers will do. They won’t get by on their looks if they have a bitter taste, and you certainly wouldn’t want to garnish your meal with anything toxic. Finally, be sure to explain to children that not all flowers can be eaten, just the special ones, such as those mentioned above.


April 18, 2017 ptillman



I am excited to get out in the yard and start gardening but I am being eaten alive by mosquitos.  Do you have any suggestions for how to control them?  Ants can damage fruit, and they also protect aphids living in the trees.


We have had a long wet winter this year. Now that the rains are subsiding, this is time to think about mosquito control.  There are many species of mosquitoes; most do not pose a problem to humans or our pets but a few mosquito species do pose a serious threat.  More than 50 species of mosquitoes occur in California, with habitats ranging from deserts at or below sea level to mountain meadows with elevations of 10,000 feet or higher. Many of these species are relatively uncommon and seldom pose a threat to human health or well-being.


The few species of mosquitos that cause serious health issues such as West Nile Virus in humans and heart worm in dogs like to breed in stagnant water. Only female mosquitoes suck blood; the males live on nectar. Female mosquitoes lay their eggs in stagnant or very still water so it is very important to make sure all possible breeding areas such as buckets, pots and old tires are drained. Check tree crotches and fill them with dirt or water absorbent material if they contain water; empty bird baths and refill them daily. Even small containers such as soda cans, glass jars, flower pot saucers, or tree holes can provide a habitat for mosquito development.


The most effective control methods are those that kill the mosquito in the larval stage of the life cycle. Keep in mind adult mosquitoes can fly several miles from where they develop. Even successful control of mosquito larvae on your premises might not result in eliminating mosquito numbers or biting activity.


Besides eliminating places that might hold stagnate water don’t forget to place some mosquito fish in animal troughs so the fish will eat the larvae. Do make sure to prevent these fish from entering any waterways as they may become invasive.  You can also use the mosquito control rings contain Bt israelensis, a naturally occurring bacterium that kills mosquito larvae for a full 30 days. They are slow-release, floating Control Ring that will kill larva in your pond or water garden.


Most mosquito bites occur at dawn or dusk; if you need to be outside during these times wear long sleeved shirts and long pants and if there are a lot of insects around, it may be necessary to spray your clothing with a mosquito repellant. Lastly, check the screens on the windows of your home to ensure they are snug and have no holes that the mosquito can get through.


For more information about Mosquitos and ways to control them around your home check out the pest note for mosquitos at the UC IPM web page.



April 10, 2017 ptillman




Since the drought ground squirrels have taken over my yard.  They have built burrows in my orchard and now this spring they are chewing on all the new vegetable starts that I have set out. I notice that they have even stripped some of the bark off the fruit trees I planted this winter. What can I do to rid my yard of these pests?




California ground squirrels (Spermophilus beecheyi) are indeed a formidable garden pest that can be hard to control. They will, as you point out, eat virtually any growing plant, and their burrowing can also be very destructive to trees and hazardous to livestock. According to the UC IPM website “ground squirrels live in a burrow system where they sleep, rest, rear young, store food, and avoid danger. The burrow openings are about 4 inches in diameter but can vary considerably. The burrows can be 5 to 30 feet or more in length and can extend 2 to 4 feet below the soil surface. Often there is more than one opening in a burrow system. Ground squirrels live in colonies that can include several dozen animals in a complex of burrows.” 


To discourage population buildups, remove brush piles and debris, and destroy old burrows at least 20 inches down. Since the California Fish and Game Code classifies them as nongame animals, property owners can use any method to remove them. The main methods of control are trapping, fumigation and baiting.


Trapping can work during all seasons except winter.  The best trap I have found for catching ground squirrels is the Squirrelinator trap.  However you have to be prepared to then dispose of the live squirrels. Touching trapped animals, is not recommended since ground squirrels can harbor bubonic plague and other diseases.


This time of year fumigation can be a better means of control then trapping. Since ground squirrels breed only once a year in the spring time fumigation can work well to control populations. Timing of breeding varies with location but in the Central Valley ground squirrels breed February through April.  Aboveground activity by adults is at a maximum at the height of the breeding season. The young are born in the burrow and grow rapidly. When they are about 6 weeks old, they usually start to emerge from the burrow.  Fumigation works from early spring to early summer as long as the soil is still damp. When using fumigants read and follow all label instructions. Some fumigants can produce flames, or have fumes accumulate that may leak into a building if burrows are to close, so use cation when using this method of control.


Later in the summer baiting may work to remove the ground squirrels as this is when they’re eating seeds and will be more drawn to the baits. If you do bait make sure to use bait stations that do not allow pets to gain access to the bait.


For more detailed information on ground squirrels and the different methods of control or to see plans for an easy to build bait station visit the UC IPM website at


March 20, 2017 ptillman



This time of year there are many questions about what folks should be doing in the garden and when they should be planting.


Here is a list of what to do in the early spring garden.

  • Prune grapes vines as soon as you see any buds sprouting on the ends of the canes. This will prevent the vines from leafing out too early and getting damaged by late frosts.  
  • For your peach trees, remove curled leaves and destroy them and any fallen leaves to reduce peach leaf curl.
  • Once they are done blooming, cut back early spring flowering shrubs that bloom on new wood (Forsythia and Quince, for instance).
  • Mulch cane berries, cut out all old canes and reset new canes in twine.
  • Get weeds under control- Cultivate, mow or pull now!
  • If weather permits, prepare beds for planting by spading in compost and other soil amendments.
  • Check irrigation systems for leaks or other problems and perform maintenance as needed.
  • Divide and replant herbs and other perennial plants.
  • To prevent sunburn and borer problems, paint young tree trunks with water based interior white latex paint 1:1 with water.
  • If you know you’ll be using shade cloth to prevent sunburn on peppers or frost protection cloth to protect delicate seedlings, erect frames for it now.
  • If you use organic fertilizers such as alfalfa meal, fish bone meal or green manure, dig them into your beds now. Soil organisms need time to break these down and deliver nutrients to your plants.
  • Now is the time to fertilize cane berries and strawberries.
  • Fertilize all deciduous fruit and young shade trees at first sign of leaves also any young conifers and roses.
  • Start fertilizing Citrus trees this month. Citrus trees are heavy nitrogen feeders. Mature trees need 1 ½ lbs. N per year. Divide this amount by 4 and apply each quarter one month apart for next 4 months.
  • This is also a good time to fertilize Daphne and camellia with NPK bloom.
  • Check roses for black spot, mildew and rust and spray or dust with sulfur only if needed.
  • Watch for early signs of powdery mildew on grapes, roses and ornamentals such as lilac. Treat at 2-4” of growth if needed. Apply sulfur or potassium bicarbonate once per week when temperature is below 90 degrees.
  • Check roses for aphids; you should be able to control with a strong spray of water or insecticidal soap.
  • Make sure critter-proofing fences and wire are intact, and repair them as needed.
  • This is a great time to seed and renovate lawns if needed.
  • Aerate and fertilize your lawn, starting this month.
January 31, 2017 ptillman



What should I be doing in my yard and garden this time of year?



When we get a break in the rains this is a good time to get your trees and shrubs ready for spring.  Late winter is the best time to prune grapes, roses, crepe myrtle and any fruit trees that have not bloomed yet.  You may also want to cut back any dormant grasses or perennial plants that have not already been cut back.


This is also a good time to paint the trunks of newly planted trees and to repaint the trunks of young trees to prevent borers and protect from sunburn.  Sunburn is the number one cause of much of the damage I see to trees around Redding.  To paint, use interior white latex paint with equal amounts of water and apply generously.


Now is the time to control slugs, earwigs and sow bugs with bait or traps before you plan to set out yummy young seedlings. By getting the populations under control now you will not be losing plants to these pests later in the season.  Make sure to use baits that are not toxic to pets.


Remove and discard old flowers from azaleas and camellias to reduce petal blight, cleaning up around these shrubs after bloom will help control fungal infections.  Roses also benefit from this sort of attention, if they have not already been pruned back.


Divide perennials such as asters, lilies, perennial phlox, and chrysanthemums, by dividing you will rejuvenate the plants and also have plants to share with fellow gardener or plant in other places in you yard.


Late February is a good time to fertilized Daphne, after bloom, and asparagus, strawberries and apply the first fertilizer to cane berries.  For cane berries, you want to split yearly recommended amount into three applications, just before new growth, mid-spring and mid-summer.


If the rains let up, you may have time to get in one last dormant Spray: Check the California Backyard Orchard website ( for specific information on your trees. But rule of thumb is to spray all fruit and nut trees, if not done in January, before bud swell.


Apricot trees should be sprayed with a fungicide containing copper to prevent brown rot. Spray at bud swell, full bloom, and petal fall.


Remember if you plan to add to your orchard or yard, this is the time that Bare-root deciduous shrubs and trees are available so check your local nurseries to get the best selection.