Monday, January 13, 2020

Pruning time on California's Central Coast

Most hybrid teas and floribundas will produce better quality, more disease resistant bushes if they get a good pruning in January in Coastal and Southern California.
Escapade, 1967, Floribunda

Pruning Fundamentals

Here are the basic steps to effective rose pruning of hybrid tea and floribunda roses:

Prune away all dead and dying canes, all canes which are growing across the center of the bush, any growth that’s thinner than a pencil, and any broken or damaged canes. Your goal is to open up the center of the bush. Each cut should be about ½ inch above an outward facing bud eye.

Remove canes which cross through the center of the bush.
Pay no attention to any new growth, including flowers and buds, which may appear on the ends of canes. Pretend they don’t exist and prune accordingly. (The flowers they produce at this time of the year are substandard and are likely to drop their petals soon if put in a vase.)

Escapade thinned out and ready to be weeded

Look for incidents of cane on cane on cane on cane. Most established plants will have several. With each successive cane, you’ll notice that they are increasingly thinner and stubbier. Prune down to either the first or second growth.

Time to remove cane on cane on cane branches. The base is old and everything growing out of it is much smaller.

Pull off all the leaves from last season. Push off any new sprouting growth. That seems counter-intuitive but this new growth is likely to be weak and also a haven for fungal spores and perhaps insect eggs. Pretend it’s not there and prune.

Dublin Bay, 1975, large flowered climber, ready to be pruned

Then, rake up all of the old leaves and mulch and discard it. This is particularly important if your roses have been suffering from insect attack. Their eggs and/or larvae often winter over in the old leaves and mulch.

The height of your bushes is a personal preference and dependent on the specific variety. However, aim for a height which is 1/3 shorter than what you see at the moment and with far fewer canes.

The general rule is prune hard and you will get larger better formed flowers, prune lightly and you will get smaller flowers but more of them. Hybrid teas are better with a hard pruning. Floribundas are better with a lighter pruning. 

Many rosarians have noticed that yellow-flowered roses take more time to respond to a hard pruning.

Put all your pruning trash in the waste bin not in your compost pile. You aren’t likely to have hot enough temperatures in it to kill the fungal spores.

Dublin Bay pruned and ready for weeding and cleaning.

 Climbers need a special type of pruning with the aim of creating slanting and horizontal canes. The flowers on climbers will come from short flowering stalks. The more horizontal the cane, the more stalks will emerge. It's vital to encourage climbers to grow where you want them. Canes growing from the bud union out into open space have been removed in the photo above so that the remaining canes will grow up and along the fence.

Lavender Lassie, 1960, hybrid musk is stretched horizontally. Each bud eye on the short stubs will produce flowering canes

Additional pruning tips

Pruning is much easier if you continually resharpen your bypass pruners.

If you are like me and have to prune over the course of several days, prune the roses growing in the darkest areas of your garden first and those in the sunniest areas last. This way, as the sun rises higher in the sky, the darker areas will eventually get more sunlight and begin to grow. Those in the sunniest and warmest areas will easily catch up, putting your entire garden on the same bloom cycle.

As a final note, a little bit of pruning even into the first week of March is better than no pruning at all. Even if you merely cut the tops like you would a boxwood edge.

Remember that one of the best reasons to prune is sanitation and disease control.  The more air that is allowed to circulate around the rose bushes the better they'll be able to fight fungal diseases such as black spot, powdery mildew, rust, and botrytis.

May your roses in 2020 be the best ever.

Escapade in full flower.

Wednesday, October 2, 2019

Gardening in a Mediterranean Climate in the Fall

My recent conversation with U.C. Santa Cruz Arboretum's executive director Martin Quigley. If you want to know more about growing things along California's Central Coast, this is a must watch video.

U.C. Santa Cruz Arboretum's Succulent Garden

We define a Mediterranean climate and discuss their unique qualities, talk about growing fruit trees, ornamental plants, and bulbs, review fine points of pruning trees and flowering shrubs and separating succulent plants.
Specimen plant at the Arboretum

Golden Delicious apples in Corralitos, California

Australian Ghost Eucalyptus

Succulent sprouting flat at a Watsonville nursery

Desert garden display at the U.C. Santa Cruz Arboretum

It was a fun interview which took place at the KSQD Santa Cruz studios on Saturday, September 14, 2019. The video is 20 minutes long and contains nearly 100 different images.

Monday, June 17, 2019

Crown Gall In Your Rose Garden

Crown Gall growing on Tournament of Roses

Agrobacterium tumefaciens and your roses
Joe Truskot, Master Rosarian

Basic Questions
What are galls?
 Outgrowths of plant tissue, Reprogrammed cells, Tumors, Not parasitic growths like mistletoe
What causes galls to form on many plants?
Insects including wasps, aphids, flies, various fungi, bacteria and viruses
What causes galls to form on roses?
Bacteria in the soil, Agrobacterium tumefaciens
Which roses are most susceptible?
Roses in the ground for more than 3 seasons, grafted roses (more so than own root), bare root roses with broken prominent roots, dug up and transplanted roses
How do the bacteria enter the bush?
Weak grafts, injured roots, frost damage, and, unintentionally, moles other ground diggers
What are the signs of a crown gall infestation?
Decreasing performance, fewer basal breaks or strong canes, decline in candelabras or flower sprays,
Small/spindly canes from the bud union, lack of normal vigor, sudden death of major canes, food/water/ sunshine – don’t help

Stem gall on a rose cane and root gall on lower root
Options and Remedies
Do nothing.
No cure - but it grows slowly, too late for amputation, vigorous roses will live for years with it, hardened galls are safe houses for earwigs and insect larvae
Do surgery.
Sharpen your hatchet, scrape down to the greenwood, disinfect with vinegar, alcohol or bleach solutions
Dig up and discard.
Remove affected plant/galls/soil, salvage what you can, make cuttings in fresh soil, add plenty of green manure to the area, plant annuals and cereal grasses from seed, let 2 or 3 years go by before planting roses in that spot
Biological Control.
Galltrol uses a strain of freshly grown Agrobacterium radiobacter
Commercially available Gallex.
Dig all around the base and discard soil, remove as much of the gall as possible, leave exposed for two days, paint on the Gallex and let dry for 2 days, replace with fresh soil
Buy a new rose.
Prepare new roses.
Soak bare root roses in a weak bleach solution (1/4 cup bleach to 5 gallons of water), kills surface bacteria/insect eggs, rehydrates the bush
Remove Bindweed.
Wild morning glory can serve as a host (bindweed, Ipomoea leptphylla), birds eat the fruit and scatter the seeds, bacteria clings to bindweed roots
Help the rose defend itself.
When injured, plants release phenolic compounds. Phenols are sent to the injured area to heal the wound. Most plant scars are a result of the phenols in action. Hungry, thirsty roses can’t produce enough phenols.
Where do phenols exist?
Phenols are present in the food we eat, found in plants used in traditional medicine, some phenols are germicidal and used in disinfectants
Healthy soil is inviting to surface critters as well as earthworms, grubs and a panoply of microbes below ground

Components of Healthy Soil
Sandy loam:
Good drainage, adequate air circulation, easy for rose roots to grow, composition is 50-70% sand, 15-20% clay, and 15-20% silt
Organic material:
Controls pH factor, provides nutrients, retains moisture
Microbial action:
Breaks down organic material, provides environment for earthworms, warms the soil, certain bacteria and fungi help a rose’s immune system, protect against pathogens and other threats, fungi colonize plant roots and create mycorrhizae which greatly extend the reach of the roots
Microbes in Healthy Soil:
Part of a rose’s digestive system, recycle water and break down nutrients, overuse of chemical fertilizers and pesticides harms microbes
What do mycorrhizae do?
Mycorrhizae help similar plants communicate, produce chemicals that repel pests and attract predatory insects, mycorrhizae are covered with a protein called glomalin which is composed of 30 to 40 % carbon. Glomoalin fixes carbon in the soil. Ninety percent of all organisms on the planet live underground.
What are bacteria?
One-celled microscopic organisms are oblong and rod-like, one teaspoon of healthy soil contains from 100 million to 1 billion bacteria, bacteria dots the surface strands of fungi
What are the four bacteria groups?
Decomposers: convert energy in soil organic matter into forms other organisms can use
Nitrogen fixers: from air to soil
Chemoautotrophs: obtain energy from other than carbon (nitrogen, sulfur, iron, hydrogen)
Pathogens: includes Agrobacterium tumefaciens which create galls
What do bacteria do?
All four groups of bacteria help water retention and the movement of water in soil, nitrogen fixing: from air to soil, nitrifying: converting ammonia to nitrite, denitrifying: anaerobic (water-logged soil) release nitrogen, release stored energy in the form of heat
What are actinomycetes?
More highly evolved than bacteria but not quite a fungus, best at hard to degrade cellulose and chitin at high pH levels, the smell of healthy organic soil means actinomycetes are present
What are the benefits of Agrobacterium tumefaciens?
Scientists have converted (“disarmed”) it into efficient delivery systems for genetic manipulation. The transgenes must be stably integrated in the host genome. Agrobacteria largely modify the host, particularly its defense-related genes. Agrobacteria largely shift the “hormone balance” in their infected hosts. This effect on endogenous growth regulators will ultimately lead to agrobacterium-induced tumor formation. This property makes genetic modification possible

Monday, March 25, 2019

Time to Feed

New foliage on Lavender Lassie, hybrid musk
The days are definitely getting longer and, most importantly, warmer. With six inches of new growth on most rose bushes that were pruned back in January, it's time to give them something to eat.

I say "something" because they do require a steady intake of nitrogen, phosphorus, and potassium. That's the N-P-K that must appear on every bag or box of commercially sold fertilizer.

Remember that the forms of nitrogen and potassium that are readily available for plants are water soluble. Given the huge downpours we've had this winter. It's likely that much of the nutrients have drained out of the soil beneath your garden are now beyond the reach of the roses and other shrubs.

New foliage on Gloire des Rosomanes (Ragged Robin) hybrid china
If you are committed to organic sources only, get those fertilizers in the soil now. You'll need to work them in somewhat so that the microbes which convert them into usable forms can get to work. Make sure that there is plenty of light reaching the soil so that the soil temperature heats up to maximize the microbial action.

You can also use chemical fertilizers now as well and not have to worry too much about the roses being sufficiently hydrated. Just make certain that after you apply the Triple 16 or Triple 10, you water and water well. The nutrients need to dissolve and reach the roots of your plants.

If you haven't given your roses any Epsom Salts in the past three or four years, give each hybrid tea approximately a half  a cup and water it in. Epsom Salts are magnesium sulfate. Magnesium helps all plants transport nutrients from the ground up through the stems and canes into the leaves and thus stimulates plant growth.

The recent rains are slightly acidic which most ornamental plants love so you should see some very healthy growth in the garden right now.

New foliage on Maria Callas, hybrid tea
As most folks who follow this block of come to understand, I buy my fertilizers based on price. Whatever is cheapest is for me. Plants can't tell whether the fertilizers are organic or non-organic. The benefit of using organics such as fish fertilizer or guano is based on what else is coming with the nutrients. You can bet that food sourced from the ocean will contain most of the minor and micro nutrients all plants need. Food from agricultural sources such as cow or chicken manure will also contain abundant organic material that helps to amend the soils and ensure that future growth can depend on them once they break down.

I just purchases a box of MiracleGro at a really good price. I dilute it beyond the recommended amount believing a little every time I apply regularly is better than a bunch two or three times a year.

I'm likely to give my garden something to eat perhaps every two weeks through the summer. My feeding schedule is a little bit goes a long way if you do it regularly.

Get busy. Get out there. Get your roses looking great.
New foliage on Dublin Bay, large flowered climber

Tuesday, February 12, 2019

Flowers for Valentine's Day: How to make them last longer

Roses at Salinas Walmart

Flowers for Valentine's Day: How to make them last longer

Although we should have pruned all of the rose bushes in our garden by now, I bet there might be one or two plants that haven’t been downsized yet. Perhaps you can make the best of it, if they still have blooms, and put a garden rose in a vase on Feb.14. If you do find unopened buds, you can pull off the outer petals and dunk the stem in tepid water. Place the rose in a warm, sunny spot indoors. It might not win “Queen of Show” but it will open.

How to keep cut flowers blooming longer

If you are the lucky recipient of a bouquet of commercially grown, cut roses (or purchased some for yourself) always re-cut the bottom of each stem as soon as you bring them into the house. Do this under warm, running water – if you can manage it - and place them in a vase into which you have dissolved a couple of aspirin tablets.

This is true science. Aspirin is derived from a chemical compound found in willow trees. It has the ability to counteract – at least for a time – the onslaught of rot and encourage the stem to uptake water. If the stem still has prickles on it, put your leather gloves on and push them all off. The rose will take in water from the area where the thorns once grew.

Continue to further refresh your stem cutting every two or three days and replace the water.

If you get a bunch of tulips, take the time to prick the peduncle of each flower with a pin. That’s the green part between the petals and stem. This allows the pressure to escape and the tulip won’t spend as much energy opening and closing as it responds to daylight. This procedure should allow them to last a few days longer.

A mixed bouquet will also benefit from the treatment above. The different cut flowers will have different life spans. As they drop petals, remove them from the arrangement.

Carry the vase and flowers out to a cool garage for the night and return it to the breakfast table. That should also extend the bloom.

Celebrate with flowers

Chocolate and wine are nice but ... remember the New Year's resolutions to lose a few pounds?

Buying flowers, especially for no occasion whatsoever, is a great way to lift your spirit and the spirits of those around you. Bring vibrant colors into your home when the skies are gray and the air is chilly. It also keep our floriculture businesses alive.

"In The Garden with Joe Truskot"

The Monterey Bay Area's new garden show airs on KSQD 90.7 Santa Cruz, Saturdays at 9 a.m. PST. Give it a listen. Featured guests: Feb. 16 Joe Ghio, Feb. 23 Stephen McCabe. Streaming at

Thursday, February 7, 2019

In the Garden with Joe Truskot airs on KSQD 90.7 Santa Cruz

Special guests and lots of practical information about gardening along California's Central Coast. We are streaming live every Saturday, 9 to 9:30 a.m. PDT at