Sanhedrin Nursery – Garden Blog

• Feed camellias, azaleas and rhododendrons with an acid plant food now. Remove dead flowers and mulch to keep the soil cool.

• Plant fresh herbs from young plants. Basil, rosemary, thymes, mints and sages are just a few ideas.

• Check roses for black spots on the leaves and treat immediately to prevent defoliation.

• Hydrangeas have giant pink or blue flowers. They will brighten the shade garden all summer.

• Meyer lemons, with their sweet-scented blossoms, are attractive and easy to grow. Plant one in a container so you can move it to a protected spot in the winter.

Fireblight on Pear Trees

“The last time you went out to check on your orchard, the pear trees were setting fruit and everything seemed fine. But all of a sudden, it looks like someone took a torch to whole branches of it and now the tree looks dreadful.”

If this sounds familiar to you, chances are your pear trees have fire blight. Fire blight is a destructive disease common on pear, Asian pear, quince and sometimes apple trees. It also affects pyracantha, cotoneaster, hawthorn and some other related trees and shrubs. The disease can destroy limbs and even entire shrubs or trees if left unchecked.

Fire blight actually starts in the spring with a light ooze from cankers on branches, twigs, or trunks. The ooze turns dark after exposure to air, leaving streaks on branches or trunks. However, most cankers are small and inconspicuous and infections may not be noticed until later when flowers, shoots, and even young fruit shrivel and blacken.

The infection usually enters through the flowers and then moves down the branches, infecting fruit, leaves and stems as it goes. Dead, blackened leaves and fruit are the result which give the tree a scorched appearance, hence the name “fire blight.”

In warm, moist spring weather, the disease becomes active and usually infects the blossoms if it rains while the tree is blooming. This year it seems that conditions were perfect for fire blight, and we are seeing a lot of customers with this problem.

Once it has infected a tree, the only thing to do is to prune it out. You must prune at least 8 inches below the damage. This often means also removing a larger branch to which the infected branch is attached. This is necessary because the infection spreads down into the tree ahead of the visible portion.

Dip pruning tools in 70 percent isopropyl alcohol (rubbing alcohol) or 10 percent bleach solution (1 part bleach to 9 parts water solution) between each cut. Wash and oil shears when you are finished. Dispose of all infected plant material.

Next winter, you can spray your trees to help prevent fire blight. Copper sprays can be used before bud break – when leaves emerge from the buds. Streptomycin (an antibiotic) can also be used from bloom through petal fall period to prevent infection from occurring. Repeat the spray at 4-day intervals through the bloom period, but do not apply streptomycin when the maximum daily temperatures are below 65°F.

Any excessive amount of new growth on your tree is easily susceptible to fire blight infection, so use only low-nitrogen fertilizers on susceptible trees. Be sure to completely clean up around your trees this fall, picking up any dead twigs and mummified fruit on the ground, and disposing of them.

This has been a particularly bad year for fire blight in California. Trees bloomed early, and warm, moist weather spread the disease rapidly. Pruning is your best option to control the disease this year.

• There’s still time to plant summer vegetables: tomatoes, peppers, zucchini, cucumbers and corn will bear for you if you plant them now.

• Fertilize hanging baskets every 10 to 14 days with a liquid fertilizer. Pinch off faded blossoms and they will keep blooming all summer for you.

• Spray roses every two weeks with Neem oil to keep leaves free of black spot and mildew.

• Attract birds to your garden with a concrete bird bath. They come in many attractive styles and make good gifts.

• Pepper plants should be fertilized when the first blossoms open.

Trees for Shade and Beauty

When the summer heat comes on, we quickly appreciate the value of a shade tree. Shade trees can be different sizes depending on their location and whether you want to shade a small patio, or part of the house.

When choosing a tree, it is always best to first determine which trees are best adapted to the planting site. Then you can consider tree function, size and shape, flowers, leaf color, or other outstanding features. Trees provide us with many benefits from shade and beauty, to erosion control, wildlife habitat and stream bank stabilization.

For a fast-growing shade tree, look for a Raywood ash or a Fruitless mulberry. The Raywood ash grows more upright when young, eventually becoming a dense, round-headed tree. Its burgundy fall color is very attractive. Fruitless mulberries quickly make an umbrella of shade. The large leaves turn bright yellow in the fall and are easy to clean up, but the catkins can be messy in the spring.

Maples and sycamores make fine, large shade trees. October Glory maple is a beautiful, round-headed tree growing 40 feet tall. It has striking bright red to orange fall color. Summer Red™ red maple is a fast-growing shade tree, 35 ft. tall and 20 ft. wide, with orange-red-purple fall color. It forms a dense, broad tree providing welcome summer shade.

Our native Bigleaf maple, Acer macrophyllum, has huge maple leaves 6-12 inches across. It can grow up to 50 feet tall but is normally more like 30 feet. It likes to grow along streams but will also grow on drier sites. In the fall, it stands out in the forest with its bright yellow leaves.

London Plane trees, or sycamores, grow 50 feet tall and 40 feet wide and have naturally shedding bark that makes a very attractive trunk. Their large, maple like leaves turn yellow in the fall. Bloodgood is a disease-resistant variety.

Pink Dawn Chitalpa is a smaller, deciduous tree that is fast-growing to 25 feet tall and wide. It has long, narrow, bright green leaves that form a background for the large clusters of trumpet-shaped pale lavender flowers that bloom all summer. Once established, it needs only occasional watering.

For a smaller tree with showy flowers, you might choose the popular red-leaved Krauter Vesuvius flowering plum. It grows 15-20 feet tall and wide with light pink single flowers in spring and purple-red leaves all summer. The double pink flowered Prunus blireana has beautiful spring blossoms. Its purple foliage turns greenish in the summer.

Flowering crabapples make fine smaller shade trees with their showy spring flowers, broad canopy and colorful fruits. Prairiefire flowering crabapple has dark purplish-red flowers and colorful fruit and grows to about 20 feet tall. They make fruit that is enjoyed by the birds but can be messy around the patio or walkways, so be sure to plant them where the fruit-drop will not be a problem.

Weeping willows grow 30 to 50 feet tall, with equal spread. Their weeping branches will reach down to the ground, if left unpruned, making a magical and shady gathering place underneath. They need lots of water and room to grow, but an old weeping willow is a friend long remembered.

For a cool, shady place to relax on hot summer days, “trees are the answer!”

• Attract hummingbirds to your patio this summer with hummingbird feeders, so you can enjoy their iridescent beauty and charm. The new Big Gulp™ holds 40 oz. and is easy to fill.

• Azaleas, camellias and rhododendrons can be pruned now without sacrificing next years bloom. Ask at your nursery if you need help.

• Paint trunks of young fruit trees with Tree Trunk White. This will keep the soft bark from sun-burning which leaves cracks for borer insects, the most common cause of death of young apple trees.

• Earwigs are out and about and hungry. Control them with the new “Sluggo Plus”, which has the natural, bacteria-based spinosad added to the original iron phosphate formula.

• Stake or cage tomato plants before they get any larger.

Bright and Sunny Marigolds

Marigolds have a long and rambling history traveling from their native Mexico, where they were used and admired by the Aztecs, across the ocean to Europe and African and finally back to America. Through their meandering journey, some varieties became known as African marigolds and others as French marigolds.

Since the 1920s marigold breeding has developed hundreds of new varieties. The glorious marigold flowers come in all the colors of the sun – brilliant yellow, bold orange, rich gold and russet tones, and bright white. Their diversity of flower types and drought tolerance make them a very valuable bedding plant for summer gardens.

African marigolds are both the largest marigold plants and the largest flowers. Standing up to 3 feet tall, their large, fully double flower heads can be 3-5 inches across. They come in yellow, gold, orange and primrose (light yellow) and make fine cut flowers.

The largest of these are the Crackerjack marigolds. This is a fine, open-pollinated heirloom variety that will bloom all summer with hardly any attention. The Lady and Perfection series offer plants that grow 18-24 inches tall with blooms that measure 3-4 inches across. The Inca and Antigua marigolds are a little shorter, at around 14-16 inches tall with sturdy stems and flowers up to 3 inches across.

French marigolds are a different species of marigold and offer more variety of flower shape and color. They are bushy and compact with small flowers, up to 2 inches across, and a neat overall appearance. The plants usually grow 8-12 inches tall, and the flowers vary from single to semi-double to fully double. They come in both solid and bi-colored types in yellow, orange and mahogany-red.

You’ll find regular French marigolds with names like Yellow Boy or Janie Orange. The semi-double types are often bi-colored with red and yellow flowers and names like Durango Bee or Safari Red. The ruffled petals give them a very showy appearance.

A third type of marigold has flattened petals in a single layer with a central tuft. They are called Signet marigolds and Disco is a popular mix. They bloom early and abundantly on compact plants with delicate, lacy foliage, and are excellent for edging beds and in window boxes.

Triploid marigolds are a cross between African types and French types. Since they set no seed as they mature, the plants will produce flowers continuously over a long season. Zenith and Nugget marigolds are triploids.

All types of marigolds prefer full sun and grow in almost any soil with dry to moderate moisture. While the marigolds are an attractive addition to the garden, research studies have concluded that they aren’t effective in reducing insect damage on vegetable crops.

Enjoy this versatile flower in your flower beds and borders.