Sanhedrin Nursery – Garden Blog

• Plant Beets now for fall harvest. They will have a deeper red color than beets planted for spring harvest, and tend to have higher sugar levels too.

• Fall vegetables can be planted now for a fall harvest of broccoli, Brussels sprouts, cabbage, chard and lettuce.

• Trim grapevines to allow more sun to reach the fruit and sweeten the grapes, if they are being shaded heavily by the foliage.

• Feed fuchsias, begonias, summer annuals and container plants to keep them green and blooming right up until frost.

• Divide Oriental poppies and bearded iris now. Add some bone meal in the bottom of the hole when you replant them.

Exotic Pest Plants

For many decades the nursery trade has been introducing plants gathered from around the world into our gardens. Any plant that is not native to an area is called an “exotic”. Most exotics are great additions to our gardens, and many tolerate garden conditions much better than the native shrubs.

But when an exotic plant becomes a weed, reproducing on its own in the wild, it is a pest plant. Pampas grass is a typical example. Introduced from South America, it now grows wild along the coastal areas of California. Scotch broom, which takes hold in disturbed soil such as along roadsides, is also a big problem in this county.

Why are these plants a problem? Because when they are so successful at reproducing in non-native areas, they crowd out the native plants that are critical for the survival of native birds and other wildlife.

Many of these pest plants are indeed weeds even in their native environment. Yellow star thistle, one of the most widespread of these weeds, came from Russia in the 19th century in alfalfa hay. It now covers countless acres of California’s hillsides, giving the “green and gold” a bluish cast. Others have intentionally been sold by nurseries for ornamental purposes but have turned out to be weeds.

An exotic plant’s ability to reproduce requires optimal conditions. So a particular pest plant will only be a pest in certain regions.

Many plants are particularly a problem in wet areas or around ponds. Cattails and umbrella plant can be very invasive, spreading by both roots and seeds. Yellow water iris has very aggressive roots which can fill up a small pond quickly.

If you have invasive plants on your property, try suffocating small seedlings and annual plants. Place double layers of thick UV-stabilized plastic sheeting, either clear or black, over the infestation and secure the plastic with stakes or weights. Make sure the plastic extends at least five feet past the edge of the infestation on all sides. Leave the plastic in place for at least two years. This technique will kill everything beneath the plastic—invasive and non-invasive plants alike. Once the plastic is removed, sow a cover crop such as annual rye to prevent new invasions.

Mowing or cutting plants down to the ground is also effective but only if you are committed to it. You will need to mow the area three or four times a year for up to five years. This will eventually exhaust the root system and kill the plants.

Herbicides are another option but must be used with caution.

Be careful about choosing plants for wild areas of your property so that you don’t contribute to the problem.

• Impatiens will give you instant color in shady areas and continue blooming right through the fall.

• Sow lettuce seeds now for a fall crop or set out plants. Set out broccoli and cabbage plants too.

• Take care of your roses: feed, water, weed, mulch and remove faded blooms regularly. Spray if necessary at first sign of insect or disease problems.

• Feed rhododendrons, azaleas and camellias with a “bloom” fertilizer to encourage flowers for next spring.

• Wisteria trees need to be trimmed throughout the summer. Keep long tendrils trimmed back to maintain the shape of the tree.

Fruit Harvesting Time

Fruits of all kinds must be harvested on time, at the proper stage of maturity in order to maintain their nutrients, quality and freshness. Harvesting should be done early in the day, when possible, and fruits should be handled gently so as not to bruise it.

Only apples and pears are suitable for long-term storage, and some varieties of those store better than others. Other kinds of fruits, like peaches, apricots and plums, can only be stored for short periods of time. They can be preserved for winter use by canning, freezing or drying.

To decide when to harvest apples, watch for the fruit to begin to change color and then sample a fruit or two to check for characteristic flavor and smell. Yellow or golden varieties change to a golden surface color when ripening.

Some varieties of apples release easily from the tree as they begin to ripen, and should be picked right away. Other varieties mature over a long season and should be picked as they mature. Apples will continue to ripen after picking. Separate varieties in storage as some will store for several months and others for less time.

Cherry season is over for this year, but cherries should be picked when the fruit is juicy, rather soft and full-flavored. They hold their best quality if picked with the stems on. Cool the fruit immediately after harvesting and they will store for up to two weeks.

Peaches should be taste-tested for ripeness. The fruit softens and becomes juicy and luscious as it ripens. When the fruit is easily pulled off the twigs then it is probably ripe. Peaches will not ripen any further though they may get softer. If you pick it too soon, it will never develop sweetness and flavor. Handle fruit carefully to avoid bruising, and cool it immediately after harvesting.

Pears must be picked before they are tree-ripe. Test a fruit for ripeness and harvest just as the pear flavor and aroma can be detected. If harvested too soon, they will have poor flavor and shrivel in storage. If harvested too late, they will likely be rotten at the core. Fruit continues to ripen after picking and can be stored for one to three months.

Plums soften and develop their delicious flavors as they ripen. Their color is not a particularly good guide to ripeness, so sample fruit to decide when best to pick. Handle fruit gently and cool after harvesting. Fruit will continue to ripen after picking and can be stored for a week or two.

Check Asian pear trees weekly until the fruit begins to change color. Some varieties change from green to yellow and others change from yellow to brown. If the Asian pears started out green on the tree, pick them when they turn yellow, and if the unripened pears were yellow, harvest them when they turn brown. They should feel slightly soft when pressed, but taste one to be sure it’s sweet and juicy. Wait until pears are fully ripe before picking.

Learn when to harvest home-grown fruit and enjoy their sweet, delicious flavors.

• Set out starts of broccoli, Brussels sprouts, cabbage and lettuce for a fall harvest. Spray weekly with BT to keep the cabbage worms at bay.

• Roses have more flowers all summer long than any other shrub. Plant them in a sunny location and feed monthly for continuous blooms.

• Japanese maples may be pruned now in order to shape them.

• Mottled leaves are often a sign of spider mites. Check for them with a hand lens or bring a leaf into your nursery for identification and treatment options.

• First-year fruit trees need to be well-watered through the dry weather. If they are neglected the first year, they may never be strong, productive trees.

Silk Trees for Summer Beauty

One of the prettiest summer-flowering trees is the silk tree or mimosa. A native of many parts of Asia, this tree goes by the botanical name Albizia julibrissin. It is known as mimosa because its leaves resemble those of the sensitive plant which is the true Mimosa. It is called the silk tree because it comes from that part of the world where silk is made.

This tree has very dainty foliage. The leaves are made up of many leaflets and they do curl up on cool evenings, like the leaves of a sensitive plant do when you touch them. The flowers are very showy and look like pink powder-puffs resting on top of the fern-like foliage.

The silk tree is used in parking lots, in lawns and parks and can be grown in large containers. It is popular for use as a patio or terrace tree for the filtered shade that it provides and the tropical effect. The flowers are most attractive when viewed from above, so it is nice when planted on a slope below the house.

This fast-growing, deciduous tree has a low-branching, open, spreading habit. It is often grown with multiple trunks which make a nice pattern when the lower branches are removed.

Albizia are generally tough trees. They take a wide range of soils including wet soils and poor, dry, gravelly soils. They can withstand summer drought, once established. They are fast-growing to 25 feet or more, spreading to 35 feet wide, but are easily kept to 15 feet tall with annual pruning.

Silk trees are considered to be messy trees. After they bloom they shed their flowers and then produce numerous seed pods that resemble wisteria pods. These will also fall in time. In autumn, the leaves fall at the first frost, having no fall color.

Each winter, Albizia trees should be pruned to remove dead branches, which always occur, and to thin out the tree, removing poorly attached branches. Other than that, they require little care.

The summer beauty and versatility in size of the silk tree makes it a good choice for many landscape situations.