- Author: susanne von rosenberg
Planting Bulbs for Spring Flowers
by Susanne von Rosenberg, UC Master Gardener of Napa County
It's September, and it's obvious that the days are getting shorter and autumn is on the way. One of the most pleasurable activities in a fall garden is planting spring-flowering bulbs. Spring-flowering bulbs add color to a late winter and spring garden, and the right kinds of bulbs will naturalize and reward your efforts for many years.
While we commonly refer to them all as bulbs, these spring-flowering marvels are actually five different types: true bulbs (such as daffodils and tulips), rhizomes (such as bearded iris), corms (freesias and gladiolas are common examples), tubers (cannas and anemones) and tuberous roots (like day lilies and ranunculus).
You see the most common types, including daffodils, tulips, irises, day lilies, calla lilies, dahlias and gladiolas, in many local gardens. Tulips are the most difficult to grow locally because our winters do not provide enough chill, and because gophers adore tulip bulbs. If you want tulips in your landscape, the best approach is to think of them as annuals that you will need to replant every year. Grow them in pots or put them in protective cages if you plant them in the ground. Most other types of bulbs will regrow every year, provided they get the basic care they need.
First, plant them correctly. The best method will depend greatly on the bulb type. True bulbs should be planted at a depth of two to three times their diameter. Bearded iris rhizomes, on the other hand, should be planted with the top of the rhizome at or just below the soil surface.
If you buy bulbs at a nursery, ask the staff about proper care and planting instructions for the types you're buying. If you buy mail order, the delivery should be accompanied by planting instructions.
In our area, bulbs should be planted in October or November, when the soil temperature has dropped below 60°F. All bulbs do best in welldrained soil and should be watered well after planting. If our rainy season starts at the normal time, you won't need to do any additional watering. If rain is delayed or below normal, water the bulbs to give them about the same amount of water and with the same frequency as they would get in a normal year.
Most bulbs need full sun, but some, such as calla lilies, prefer partial shade. You can plant the earlier spring-flowering bulbs under deciduous trees; they will have finished blooming by the time the trees leaf out fully and cast too much shade.
To keep your bulbs performing well year after year, let the foliage die back naturally after bloom. Those produce food that is stored in the bulb to nourish next year's flowers. Also give them a light application of phosphate-heavy fertilizer (such as bone meal) every year. After three or four years, many types of bulbs become crowded and need to be divided. You can tell that it's time to divide them when you see a lot of leaves growing in a crowded area, but you get fewer flowers than in previous years.
Many bulbs native to the Cape Province of South Africa, which also has a Mediterranean climate, will do well here and naturalize easily. Try spraxia (also known as wand flower or harlequin flower), ixia or babiana. Another interesting variety to consider is rain lily, a Mexican native (Zephyranthes) that looks a bit like a crocus and comes in many colors.
You can also plant native bulbs this fall. One advantage of natives is that they bloom when native insects need them. They are also adapted to our climate and do not require any special soil preparation.
There are more than 200 species of native California bulbs, corms and rhizomes. Some examples include Coast iris, blue-eyed grass (a very small native iris), snake lily, camas bulbs and fritillaria. The Calflora website (www.calflora.org) lists 23 native species.
If you buy native bulbs, make sure they are ethically sourced, not collected from the wild but propagated by the nursery that sells them. Because native bulbs are likely to be more expensive, it's particularly important to be well-informed about the growing conditions they require.
For example, camas bulbs prefer soil that is very moist in the spring and then dries out, conditions typical of seasonal wetlands and the edges of creeks. Give them a home in an area of your garden that is soggy during the wet season, but then dries out. They have a long flowering period (typically April through June).
Camas bulbs were used as a food source by native American tribes and are very appealing to gophers. They are one of the few native bulbs that need gopher protection. California native bulbs are a worthy addition to a native garden and also make great potted plants.
Next workshop: “Stinking Roses and Edible Alliums: Grow These Essentials for Your Kitchen” on Saturday, October 12, from 9:30 to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. For more details and online registration go to http://napamg.ucanr.edu or call 707-253-4221.
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
By Susanne von Rosenberg, U. C. Master Gardener of Napa County
One of the questions that home gardeners ask Napa County Master Gardeners most frequently is: How much should I water? As with many gardening questions, the answer is: It depends.
Watering adequately is important to avoid stress on permanent plantings such as trees and to keep your vegetables and flowers producing well. When plants don't get enough water, they have to choose between photosynthesis and survival, so they will tend to stop growing. Plants also use water to cool themselves.
You need to adjust your watering to the time of year and the weather. In Napa Valley, plants typically need the most water in early July, when the days are the longest and hottest. By the end of August, plants need about one-third less water than they did at the height of summer because the days are cooler and shorter. By mid-October, they are using only about one-third of the water that they needed in midsummer.
If you water at the same rate all season, you are likely overwatering early and late in the season and underwatering in the middle of summer. Of course, if we get a hot spell, such as the one we just had, your plants will need extra water. While we can normally stop watering when the rainy season starts in October, we've had several years recently when rain came late or not at all. If that happens, you'll need to keep watering.
Here are some additional watering guidelines:
Non-native annual plants, including flowers and vegetables, need to be watered when the soil is dry to a depth of about 1 inch. How do you know that the soil is dry that far down? Simply test the soil with your finger. You'll be able to tell if it's dry or moist. If you prefer not to get dirt under your nails, buy a soil-moisture gauge that uses electrical conductivity to determine if the soil is moist enough. Simply follow the instructions that come with the probe.
You'll want to couple the soil test with your observations. Plants will tell you when they are water stressed. If you are not watering enough, leaves will tend to get dull, and many plants will change the orientation of their leaves from fairly flat (to capture the most sunlight) to more vertical. Some plants will start to fold up their leaves.
Of course, wilted leaves are a pretty good sign that your plants need water. However, squash, pumpkin and cucumber plants are a special case as they will often wilt in the afternoon. If they recover by evening, then they do not need more water.
It's also possible to overwater your plants, which can lead to root rot and fungal diseases. Both problems can cause plants to wilt, which may make you think that you need to water even more. As long as you check your soil, you'll know whether you're watering the right amount.
What about deciduous trees? Young trees need to be watered roughly every two weeks during the dry season. One-year-old trees need one to two gallons of water per day (15 to 25 gallons at a time if you are watering every two weeks). Two-year-old trees need about double that. Three-year-old trees need five to ten gallons per day, and four-year-old trees may need as much as 15 gallons per day.
A mature deciduous tree that is 25 feet tall with a canopy 20 to 25 feet wide may need as much as 50 gallons of water per day (1,500 gallons per month). Mature deciduous trees should typically be watered monthly, although given the large volume of water they need, it may be easier to water them twice a month. Water needs for other perennial plants vary widely. Please contact the Napa County Master Gardeners for more specific information.
Most California native plants are adapted to our dry summers and need little or no water. However, newly planted natives benefit from being watered a couple of times during the summer. By the time they are three years old, they should be able to survive without additional water if we had normal winter rainfall.
During drought years, even most native plants will need some supplemental water in summer. Make sure you know specifically what your native plants need. Some may die if they receive any water during the summer, while others are adapted to moist, shady areas such as creek beds and need a consistent supply of water.
Next workshop: “Home Vineyard: Part 2” on Saturday, September 14, from 9:30 to 2:00 p.m., in Calistoga. Learn techniques to maintain your new or existing home vineyard. Workshop location will be provided after registration. For more details & online Registration go to http://napamg.ucanr.edu or call 707-253-4221.
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
By Penny Pawl, UC Master Gardener of Napa County
Every morning before I get myself together, I take a stroll through my garden. I want to see how all my plants fared through the night. Did any creatures knock over a pot? Do my tomatoes need a good shake to pollinate the flowers so the plants will make fruit? Even though I thought I watered well, does anybody need more water?
I check the squash to see if any new female flowers are ready to meet the male flowers. Although the squash bees are usually on the job, I often take this opportunity to fertilize the flowers by hand. One morning I opened a flower and found two squash bees that had slept overnight in the flower. This walk-through helps focus my day and guide me in the work I need to do.
I love these summer morning strolls. I can't do my walking tour in the winter without bundling up like an Eskimo. Besides, the garden is resting in winter. If it is not raining, I do my stroll later in the day and include plants overwintering in the hothouse.
I stop along the stroll to check out my huge fennel plant. I pick a few pieces of fennel to feed the Anise Swallowtail caterpillars in my kitchen. The newborn caterpillars look like bird droppings which is one way that Nature protects them from predators.
I look for Anise Swallowtail butterflies gliding around my garden. I stop and inspect the milkweed leaves hoping I will find a Monarch egg ; I also check out the aphids living on the milkweed. If little black spots appear among the clusters of yellow, then I know predators have been munching on the aphids.
The yellow aphids are oleander aphids and don't seem to feed on anything other than every species of milkweed I have. These aphids are Mediterranean natives, and it is thought that they entered the U.S. on imported oleander. Interestingly, oleander aphids are all female and give birth to clones of themselves.
Sadly, no Monarchs have visited my garden yet. I have read that they will be scarce this year.
On this morning the milkweed is blooming high over my head. I stop and check out the pollinator garden. The bumblebees are busy at work on the salvia. They have a favorite and I find them there early in the morning and just before the sun goes down. They are hard workers and are feeding the baby bees in their nests.
One morning, as I was snooping around the Nicotiana, I surprised a mama quail hiding in the middle. She blended in so well that I did not notice her until she moved. Almost every morning I find evidence that quail have visited my garden and taken a bath in the soil in my raised beds. They seem to prefer being as close to the plants as possible. Maybe the soil is warmer there. While the plants are still small, I cover them with bent hardware cloth to protect them.
On another morning I ran into a fresh pile of bird feathers. Apparently one of the night creatures trapped and feasted on a member of my quail colony. While I know this is nature's way, it always makes me sad. I live in the country, so I know there are coyotes, skunks, bobcats, possums, raccoons and small foxes that live alongside me.
About 20 years ago my neighbors spotted a cougar near the river. I also heard it was seen walking on Big Ranch Road during the day. I have seen some of these creatures, but mostly they are night prowlers that avoid contact with humans.
Before I am done with my morning stroll, I stop at the compost bins to see if the worms have dragged the newest materials down. I also visit with the small toads that love to live in my bins, feasting on the fruit flies. Occasionally I find a lizard or garter snake spending a few hours in the worm beds. I don't make them leave as it is all part of the nature I love.
Next workshop: “Home Vineyard: Part 2” on Saturday, September 14, from 9:30 to 2:00 p.m., in Calistoga. Learn techniques to maintain your new or existing home vineyard. Workshop location will be provided after registration. For more details & online Registration go to http://napamg.ucanr.eduor call 707-253-4221.
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
By Denise Seghesio Levine, UC Master Gardener of Napa County
Most of us have warm, fuzzy feelings about ladybugs. We feel special when a ladybug lands on our hand. We charm our children with early garden experiences and recite iconic nursery rhymes as we entreat the cheerful red beetles to “fly away home.”
Ladybugs, or lady beetles, with their shiny red shells and black dots are friends in the garden, helping to eradicate aphids and other unwanted pests.
But what about the yellow-green version? You may have noticed chartreuse, shiny-shelled “ladybugs” with 11 or 12 shiny black spots as well. The yellow versions do have longer antennae than the red versions, but so what? Are they yellow ladybugs?
These yellow-green beetles are actually cucumber beetles, Diabrotica undecimpunctata. Unlike friendly ladybugs, cucumber beetles can wreak havoc in your garden and are hard to get rid of.
Adults cause the most damage.
If you are finding large holes in the foliage of your beans, cucumber, melons, squash, corn, potatoes, tomatoes, eggplant, beans, peas, beets, asparagus, cabbage, lettuce and other vegetables, look for these little pests on top of and under leaves.
Just about all the stone fruits are also susceptible to cucumber beetles, including peaches, apricots and plums. Shoots and blossoms of peas and beans, cucumbers and melons are not safe from attack either. I do not think they eat onions.
And this really points to the problem with trying to get rid of this voracious pest. Rotating crops (not planting the same crop in the same space for a few rotations) is one of the few effective ways to control Diabrotica undecimpunctata, but how do you rotate crops effectively when cucumber beetles eat almost everything?
Cucumber beetles are about ¼ inch long with a black head. Their larvae are whitish and slender although the head and tip are slightly darker. They sport three pairs of short legs and feed exclusively on roots as they develop. They like roots of corn, beans, wild grasses, small grains and sweet peas. They can overwinter in beds where they ate your crops the previous year or move out to the weedy outskirts.
Normally at this stage Diabrotica undecimpunctata do little damage, and most plants can survive. It is when the larvae mature and your plants begin to grow and leaf out, or your next batch of seeds start to germinate and push up, that the real onslaught begins.
Newly emerged seedlings are most susceptible and can be destroyed in a few days. Once plants get large enough, they might look terrible with munched leaves and damaged fruit, but they will usually survive.
It happens like this. Beetles overwinter in your garden and surroundings. When your spring plantings begin to emerge, adults begin laying their yellow-orange eggs at the roots. Tucked in cracks in the soil and at the base of plants, eggs are invisible to all but the most diligent examiner.
When the larvae hatch, they spend their first two to six weeks eating the roots of your plants. They emerge as adults about the same time your vegetables begin leafing out. Then they begin feeding on foliage, seedlings and small plants. They can reproduce and go through this cycle up to three times each year.
So what can you do if you find these culprits in your garden? If you do have room to rotate your crops, do it. And clean the weedy outskirts of your garden so they do not have places to overwinter.
There really are no recommended insecticides. They would need to be applied too often to be effective. Botanical controls, while safer, tend to be especially short-lived in efficacy.
A better strategy is to use protective cloths or screens over your newly sown seed or just-planted transplants, removing the protection only when the plants are large enough to sustain damage or begin to flower. Removing barrier cloth at flowering is essential to allow beneficial insects to pollinate.
There is some ongoing research on the effectiveness of natural predators, but not much conclusion on the efficacy. Since cucumber beetles are attracted to cucurbitacins, some experiments have used lures containing cucurbitacin powder. The method has been effective, but there are no current plans to move ahead with such a product commercially. My own preferred technique is more rudimentary. Remember, these insects are not your friends. When I see yellow “ladybugs” on my plants, I squish them.
Next workshop: “Home Vineyard: Part 2” on Saturday, September 14, from 9:30 to 2:00 p.m., in Calistoga. Learn techniques to maintain your new or existing home vineyard. Workshop location will be provided after registration. For more details & online Registration go to http://napamg.ucanr.edu or call 707-253-4221
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
Time to Plan and Plant Fall and Winter Vegetables.
By Susanne von Rosenberg, U. C. Master Gardener of Napa County
If you are a regular reader of this column, you already know that you can grow vegetables year-round in Napa County. Growing produce in autumn and winter extends your harvest and protects the health of your soil because you are practicing crop rotation.
The biggest challenge for the novice year-round gardener is mindset. How many of us are really ready to start planning our fall edibles now, when our biggest concern is staying cool, and the best tomatoes are yet to come?
To help you get into the groove, here are a few easy things you can do now to have a successful fall and winter vegetable garden.
First, make a list of the fall and winter vegetables you really enjoy. Broccoli is a favorite for many folks, and lettuces and greens for cooking are also good choices. For more ideas on what to plant, consult the Master Gardeners' “Healthy Garden Tips: Cool Season Gardens for Napa County” (https://ucanr.edu/sites/ucmgnapa/files/153368.pdf).
Next, think about when you want to harvest. As the days get shorter and temperatures drop, plants grow more slowly. Getting them into the ground early is important. If you start broccoli seeds now, you can plant the seedlings in early September and probably harvest some by late October. But wait until mid-August to start your seeds, and your broccoli will likely take until late November to mature because it will grow more slowly than seedlings planted two weeks earlier.
Plantings that mature in mid- to late November can also be left in the garden and picked throughout the winter. Most vegetable plants grow slowly, if at all, between mid-November and mid-January. Your garden is a terrific storage location for fresh produce in the winter. Don't be dismayed if your plants look wilted after a frost; they'll make an amazing comeback as the day warms up.
How do you know what to plant when? Check out the Master Gardeners' spring/summer and winter/fall planting guides (in the Healthy Garden Tips section of our website). Use this link [https://ucanr.edu/sites/ucmgnapa/files/153875.pdf ]for detailed charts, and this link [https://ucanr.edu/sites/ucmgnapa/files/218030.pdf] if you prefer a written summary.
Now comes the most difficult question: where to plant your fall and winter vegetables? Most of us need to be creative to find room. Take a hard look at your garden. Are there plants that are not performing well? Or maybe you don't like that new tomato you tried? Perhaps you're just tired of zucchini or wish you hadn't planted so many.
A little ruthlessness will serve you well as you make space for fall vegetables. If you need more room, interplanting is a great option. Plant your fall starts among the summer plants. Fall plants, which prefer cooler temperatures, will benefit from the shade cast by mature summer vegetables.
Leafy greens can sometimes grow to maturity before summer vegetables need to be removed, but for many fall crops you will eventually need to remove the summer plants so your fall vegetables get enough light. By late September many summer vegetable plants are really slowing down and looking tired, so it's a bit of a relief to take them out.
If you can't bear to remove plants that are still producing, you can grow some fall vegetables in pots. Many leafy greens do well in containers. Look for vegetable seeds specifically intended for growing in pots. One of my favorite container vegetables is sugar snap peas. Some gardeners buy extra time for their summer vegetables by starting fall crops in one-gallon pots, then transplanting them later.
If you're still struggling to find space in your summer garden, consider growing onions, garlic and fava beans, which like to be planted later. Or focus on vegetables that mature rapidly. Some lettuces and leafy greens such as tat soi may yield a crop from seed in less than two months.
Growing mesclun (salad mix) is another option. The greens in most mesclun mixes mature to harvestable size in as little as four weeks. Also consider planting long-maturation vegetables relatively late (mid-October or later) to get a head start on your spring garden. Those plantings probably won't produce anything to harvest this fall or winter, but they will have a big head start when the weather warms in early spring.
Next workshop: “Cool-Season Vegetables: Now is the Time to Plan and Start” on Saturday, August 10, from 9:30 to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Repeated on Sunday, August 11, from 1 p.m. to 3 p.m. in Yountville. For more details & online registration for the Napa workshop: http://napamg.ucanr.edu. Or call 707-253-4221. For the Yountville workshop, go to Online Yountville registration or telephone the Parks & Recreation Department at 707-944-8712.
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
