Tuesday, June 9, 2020

Candelabras in the Garden

Summer is definitely here. With several hot days, the spring rose flush has definitely ended. The good news is that you should be seeing lots of new growth.

Secret, hybrid tea, sending up a candlebara

We were fortunate to have such an incredible weather pattern this season which developed some of the largest, most colorful roses I’ve seen in years. The hot temperatures, of course, shorten the length of time the flowers will stay on the roses. It also means that your gardening time increases as the sooner you remove the spent flowers, the quicker new growth will appear.

Hybrid Tea Candelabras

I’m happy to say that this year I’m seeing lots of candelabras in my garden. Candelabras are those magnificent new canes with a large flush of new blooms on the top. I like to think of them as a “bouquet on a stick.” This usually doesn’t happen on the first flush of blooms but comes along in the next flush. Yes, this year was a great season for good quality blooms early on but it was also, in my garden, the first time in five years that I’ve fed the roses Epsom salts and both a dry organic fertilizer and a MiracleGro type product. (There are several rip-off varieties out there and they are more or less the same thing as the original.)

Blue Girl, hybrid tea, sending up a large candelabra

These candelabras may need some tending, however. We’ve had some windy days which have knocked many of my flower-laden canes over. Get yourself some of those tiny bamboo supports and prop up these great sprays as the main cane might not be sturdy enough to support all the flowers – especially if they get wet in an odd summer shower.

Regularly, remove the spent flowers on candelabras little by little. If there’s one large flower on a short stem right in the middle of the spray, remove that bud early on and you’ll get a better looking flower spray.

Radiant Perfume: it's a grandiflora and they regularly send up large candelabras

Once the candelabra’s last flower is gone, prune it back to where it is a single stem and pick a spot where there’s a bud eye facing the outside of the plant. On some of the larger ones and where space allows, you may wish to keep two of the original four of five canes. I'd recommend pruning down to the bud eye facing outward two leaves up from where the cane branched out. This will ensure that the joint hardens sufficiently to support new, heavier growth above it.

Sacred Heart, hybrid tea, sent up an enormous spray. Only the last two flowers remain.

The Re-bloom Cycle

The cycle usually takes about six weeks. It’s also important to water and feed regularly throughout the long summer. Water is the most important factor in new growth, even more so than food. Look at the ground beneath your rose bush. If it looks dry on the surface, it probably wants more water. If the temperatures are above 80 degrees or if there have been long sustainable periods of dry air and wind, you need to water at least twice a week.

Water in the early morning, if there’s a chance of the leaves getting wet. Water in the evening, if you can hold the hose under the bush. If you are on a drip system, start watering around 4 a.m. and make sure during the day that all the emitters are in the right spot and working. Leaves which stay wet for more than four or five hours are an invitation for airborne fungus spores to attach themselves and hatch.

I like to feed the roses something about every two or three weeks during the growing season. “Something” is not a particularly helpful word, I know, but it happens to be, for me, whatever is on sale. Giving your roses just a little bit of food almost every time you water is more important than a whole lot of fertilizer a couple of times during the year. Food helps you get the maximum result out of your roses. Remember to water well the day before and then feed the next day with just a little water to soak it in.

Organic food (blood, bone and hoof, kelp meal, fish fertilizer) needs time to be in the soil and breakdown into nutrients the rose can readily absorb. If you provide a little organic every time you feed, you’ll always have something in the soil in various stages of breakdown.

For established roses, you could just stop everything right now and your roses most likely won’t die. But, you as a gardener are the tender of their ability to perform well. Keep them watered and give them food and make the effort to get good results -- it's worthwhile to your own self-satisfaction.

Thursday, June 4, 2020

2020 - A Great Rose Year

Westerland, shrub

Hands down this has been one of the most spectacular spring rose blooms in history. 

Santa Cruz rosarian Joe Ghio says it’s the best year of his entire 70-plus years of growing roses.

Along California's Central Coast, we had a chilly, dry February which came, of course, right on the heels of our pruning regime. This truly put the roses to rest. March brought us rain right when the roses started growing. Additions of alfalfa pellets and Epsom salt super kick-started the growth in my garden. I hadn’t done the Epsom salt cure in years. 

A month later, my application of a good rose fertilizer and some watering pushed the blossoms up and out. The sunny but cool days of April allowed the buds to develop and bloom gloriously.

The recent hot and sunny days hurried up the bloom cycle and now we all ended up with lots of home dead heading to do.

But before this spring is in the distant past, here are some photos of my best roses.
The Black Prince, hybrid perpetual

Blue Girl, hybrid tea

Gloire des Rosomanes, (Ragged Robin), hybrid china

Secret, hybrid tea

Isfahan, damask

China Doll, polyantha

Margaret Merril, floribunda

Rosa woodsii fendleri, species

Tahitian Sunset, hybrid tea

Charles de Mills, gallica

Isfahan, damask

Nur Mahal, hybrid musk
Sally Holmes, hybrid musk


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