Sanhedrin Nursery – Garden Blog

• Pluots are a cross between plums and apricots. Their meaty fruit has a wonderful flavor. Bare root trees can be planted now.

• Spray for peach leaf curl with copper sulfate. Peach and nectarine trees may suffer from this fungus disease without a protective spray.

• Start an asparagus bed so you can enjoy their young, tender shoots straight from the garden.

• Plant strawberry plants now for delicious strawberry shortcake this summer.

• Cabbage, broccoli, lettuce and other cool season vegetables can be started now from seed. There are many wonderful varieties available on seed racks.

Chill Out!

When fruit trees drop their leaves in the fall they go into a winter dormancy. This is important for the tree for several reasons. Shutting down for the winter protects the trees from getting damaged by cold or freezing weather. It also gives them the rest period required before the trees will bloom.

When you read descriptions of fruit trees, there is often a number of hours listed at the end of the description. This is the chilling requirement of that particular variety.

Deciduous fruit trees first need some cool weather and then some warm temperatures to start growing. Different tree species need different amounts of chilling and/or warm temperatures to begin bloom.

In general, the lower the chill requirement, the earlier a tree will bloom. Once the tree has accumulated the required number of chill hours, it will bloom during the next warm period. This can be very difficult in areas like ours where we may have an early warm spell followed by more freezing weather. A variety with a low chill requirement will flower too early and the blossoms or immature fruits will often be damaged by cold weather, especially late spring frosts. Selecting a high chill variety in warm areas will result in little or no fruit production.

Apples have the highest chilling requirements of all fruit trees, followed by apricots and, lastly, peaches. If a tree does not get a sufficient amount of winter chill, it can result in a loss of up to 50% of expected harvest.

There are several models for determining the amount of chill that your orchard receives. The “45 and under model” is the simplest and is still in use. It holds that every hour below 45°F equals one chill hour received.

The “32-45 model” says any hour of cold between 32°F and 45°F contributes one hour to satisfying a tree’s chilling requirement. According to the “32-45 model,” temperatures below 32°F don’t contribute to accumulated chill.

Other models are even more complex, but they still don’t make good predictions all the time. It is very difficult to figure out just what Mother Nature’s formula is.

Determining the exact amount of chill you receive is very difficult. Terrain can affect the chill hours too. Open slopes may receive more chilling hours than sheltered areas next to warm buildings. Locations at about 1000 feet above the valley floor may receive substantially less winter chill than the valley below.

In the Willits Valley, we receive over 1000 hours of chilling each winter. The nearest recording station is the Hopland Field Station, which receives an average of 1024 hours below 45°F and 987 hours between 32°F and 45°F.

When choosing a fruit tree for this area, varieties with at least 700 hours will do best. This is particularly important for peach trees as they tend to bloom early. But if a peach is rated for 800-1000 hours, it will usually remain dormant until the beginning of March. It will have to take its chances after that.

You will have the most success with your home orchard if you choose trees that have the proper chilling requirement for your area.

• Asparagus, whose delectable spears are even sweeter when home-grown, are available now for planting. Prepare a fertile bed for these long-lived vegetables.

• If you’re short on space in your orchard, you can plant 2 or 3 varieties of the same fruit in one large hole. This will allow cross-pollination among apples, pears, plums, cherries and Asian pears.

• Primroses, in their rainbow of colors, will light up your flower beds and boxes this winter and spring.

Growing Great Onions

Onions seem like they would be one of the easiest vegetables to grow, but raising good onions can be more complicated that it first appears. As vegetables they are interesting plants to grow because they are very dependent upon day length and temperature to form bulbs.

Onions are typically seeded in fall through early spring, harvested in early summer and used fresh or stored for winter. But as many experienced gardeners know, the crop is not always successful, and many times the bulbs produce flower heads, which is known as “bolting”.

To grow onions successfully, you must know a little about them. Onions are biennials, which means that they grow one year and makes flowers and seeds the second year. The first year the onion plant begins its growth by putting out its green top leaves in cool weather. It stores energy in those leaves until the weather gets warmer and the days get longer. Then it begins storing energy in the bulb underground. When the bulb is mature, the leaves turn yellow and die and the onion is ready to harvest.

Given a certain set of environmental conditions, onions can be tricked into believing they have gone through two growing cycles during their first year. Instead of finishing with a well-cured bulb, ready to harvest, a seed stalk can develop prematurely, causing onions to be unmarketable.

Fall seeded crops are susceptible to bolting the following spring if warm fall temperatures, allowing excessive growth, are followed by low winter temperatures and slowed growth. The most successful onions may come from transplants set out in early spring.

Occasionally other factors, such as damage by cultivation or excessive stress, may cause bolting. That’s why only a few plants may bolt in an entire plot. Should this occur, the onion will still be perfectly edible; however, as the seed-stem gets bigger, the ring inside the onion will become pithy and inedible. If left to maturity, this ring will rot quickly and cause the entire onion to rot as well. It’s best to eat the onion as soon as you see the seed-stem. Don’t bend or break the top; the leaf is hollow, and breaking it will allow water to go right into the center of the onion and cause it to rot.

Onion sets (the small dry bulbs) have a bad habit of bolting and producing a flower stem. It is actually better to plant first-year seedling onions. These come two ways: as nursery-grown seedlings in small pots, and in bunches of larger seedlings that have been grown in fields and dug-up. The latter are available now in a limited number of varieties, and the former will be available soon with other spring vegetable starts.

Onions are characterized by day length: “long-day” onion varieties will quit forming tops and begin to form bulbs when the day length reaches 14 to 16 hours while “short-day” onions will start making bulbs much earlier in the year when there are only 10 to 12 hours of daylight. As a general rule, “long-day” onions do better in north of 36 degrees latitude while “short-day” onions do better south of that line.

The long summer days that we get here in Willits, make the intermediate to long-day onions good for our climate and latitude. These include Red Zeppelin, Walla Walla, and Copra, Ruby, Candy, the Southport Globe onions, and Yellow and White Sweet Spanish.

For keeping qualities, the strong-flavored, yellow ones, like Copra, Yellow Spanish and Yellow Globe, are the best. The milder onions don’t develop the really firm outer skin needed for long storage.

Onions aren’t bothered by frost, so early spring is the best time to get them planted. Then they have plenty of time to store up energy in the leaves before bulb-making time. The more green growth, the bigger the bulbs will be. So get started with onions, now.

• Pansies will brighten your flower beds with their happy faces. They will bloom all through the spring.

• Plant seeds of broccoli, cabbage, lettuce and other spring vegetables now.

• Many fine varieties of flowering dogwoods, tulip magnolias, Japanese maples and other specimen plants are now available at nurseries for winter planting.

• Blueberries are a delicious fruit that can be planted now from young plants. Give them a rich, acid bed prepared with lots of peat moss.

• Roses should be pruned in February near the end of the dormant season. You can clean them up now, however, by removing all the old leaves on and around the plants.

Pollination Is Essential In the Home Orchard

The job of a fruit tree is to make seeds which will make more trees. The fruit is merely part of the package, from the tree’s perspective. But seed development requires pollination which can be done either by wind or insects. The pollination required by most fruit trees is performed by bees, wasps and hover flies.

For a successful home orchard, it is important to be aware of the pollination requirements of the trees you plant. Some trees are called self-fruitful. This means that their blossoms can be fertilized by pollen from another flower on the same tree. They will produce fruit even if they are far from any other tree of their kind. Most peaches, apricots, sour cherries and some apples, pears and plums are self-fruitful.

Partially self-fruitful trees will produce a crop on their own, but they will produce a larger crop, up to twice as many fruit, if cross-pollinated. Many apples and pears are partially self-fruitful.

Some fruit trees only set fruit when they receive pollen from another variety. Their own pollen is defective or sterile. Most sweet cherries, some apples and plums and a few peaches fall into this group. For example, if you plant a Bing Cherry, you must also plant a Van or a Black Tartarian or another pollenating cherry tree nearby.

For trees to cross-pollinate, they must bloom at the same time. Blooming time does not necessarily correspond to fruiting time. A late apple can bloom early, so check to be sure you are planting the correct varieties together.

A fruit tree that needs a pollenizer needs it close by. Trees should be planted within 50 feet of each other. This is because the bees that carry the pollen must visit both trees on the same trip. To protect those bees, do not spray pesticides while trees are in bloom.

To ensure good pollination, either plant the trees fairly close together, or plant a combination tree with several varieties grafted onto the same tree. You can also graft a branch of a variety with fertile pollen onto a tree that needs pollination. Crabapple trees often make excellent pollenizers for regular apple trees.

Even if you have compatible trees in place, other factors can interfere with pollination. One of the most frustrating foes of pollination is the weather. Flower buds can be injured by spring frosts or heavy rains. The more developed the bud, the more sensitive it is to injury. Fortunately, not every flower bud on the tree needs to survive to have a good crop. But each incident of frost further decreases the fruiting potential.

When you plan your orchard or decide to add a new tree to it, be sure to check on pollination requirements so you’ll be able to enjoy fruit and not just blossoms a few years from now.