- 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.
Suddenly it feels like winter. Well, not really, but the mornings are definitely brisk now and the days have cooled off. We've had a smidgen of rain. Plants have stopped blooming. What are the butterflies and bees to do?
Any poor bees and butterflies still in my garden will have to look elsewhere for nectar. But I want to fix this problem so that, next fall, I will still have some blooms for my pollen-loving friends.
I fear the drought is not behind us, so I have been looking at seeds for drought-tolerant native plants that continue blooming into fall. Native plants and our native bees, butterflies and other fauna evolved together and have adapted to our winter rains and dry summers. My water comes from a well, and because I can't see what is going on down there, I am very frugal with it.
Bees and butterflies like flowers with flat heads that make it easy to gather nectar. Sunflowers are a good example. My plan is to scatter their seeds in different areas of my garden after a rain and stomp them into the ground. Then, I hope, they will not blow away and the birds will not find them before they have a chance to sprout. However, I have noticed that those cute little quail that I have invited to live in my yard are eating the tops off of some tender plants, so I will have to use floating row cover to protect the seedlings.
After reading about the nectar plants that bees and butterflies favor, I have gathered seeds for tansy, wild senna, meadow rue, yarrow, bee balm, prairie blazing star and sea holly. Some of these are annuals and may reseed if I just let the seeds drop.
I also plan to increase the amount and varieties of milkweed (Asclepias)I have in the garden. Their flower heads are the shape that most small bees and all butterflies appreciate. And the different types bloom at different times during spring and summer. The native Asclepias speciosa grows tall and blooms in early summer. As its flowers fade and its leaves get tougher, the butterflies move to later-blooming varieties for nectar and egg laying. Asclepias fascicularis (narrow-leaf milkweed) blooms in late July and August. The bees love those flowers, too.
Hot Lips sage (Salvia microphylla ‘Hot Lips') is a favorite of bumblebees. I started with a single one-gallon plant when this variety first debuted and now I have four huge plants in my garden. It needs little water and blooms almost all summer. When I visited the arboretum in Dublin, Ireland, last June, I was surprised to see it growing there. I have other salvias, too, but they do not bloom as long as ‘Hot Lips'.
Others have told me that Asclepias curvassiva, a tropical milkweed, has naturalized in some Napa Valley gardens. It has also played host to many Monarch butterflies. The plants die down in winter and renew in the spring from self-seeding. Most bees and butterflies like its nectar. Another popular milkweed isAsclepias fruticosa, sometimes called swan milkweed because of the shape of the seed pods.
Free Tree Walk: Join U. C. Master Gardeners of Napa County on Saturday, October 22, from 9 a.m. to 11 a.m., for a guided tree walk through the lovely Alameda of Trees at the Yountville Veterans Home. Established in 1884, the Veterans Home has a unique and diverse tree collection. These majestic mature specimen trees are a focal point in the lives of the men and women who live there. Come learn more about these wonderful trees. Meet at the parking lot of the Napa Valley Museum on the Veterans Home grounds, 260 California Drive, Yountville.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
- Author: Pat Hitchcock and Jim Murphy, UC Master Gardeners of Napa
In a restricted area, such as an apartment complex or a small, confined yard, containers may be the ideal way to raise vegetables. Pot selection, container soil, container positioning, sunlight and heat deflection from walls or fences all contribute to a successful growing experience.
You can use many different kinds of containers, such as wooden planters, clay pots, plastic buckets or even plastic bags filled with planting mix. They must have drainage holes. If you are placing containers on a wooden surface, such as a deck, reduce the possibility of rot by raising the containers on small blocks to allow for air circulation.
Be sure your containers are deep enough for the crop you want to grow. Six to ten inches is sufficient for shallow-rooted plants like arugula, basil, chives, lettuce, green onions, radishes and mizuna. With a deeper pot, 10 to 15 inches, you can try carrots, celery, Chinese cabbage, garlic, leeks, Swiss chard and patio tomatoes.
Go for 18- to 24-inch-deep containers if you want to try beans, broccoli, kale, peas, peppers and short-vine (determinate) tomatoes. A container 20 inches in diameter and 18 inches deep will give you plenty of room for several small lettuces or for one pepper or tomato plant.
The planting medium needs to be both porous and moisture retentive. Because you may need to move your pots occasionally, it also needs to be lightweight. Garden soil is too dense and heavy. A good-quality potting soil will contain compost and nutrients for plants, plus vermiculite or perlite for drainage and peat or coir for holding moisture.
Finding the perfect place for your containers may be the most challenging part. Leafy vegetables such as lettuce need four to six hours of sunlight daily, but fruiting vegetables like peppers, beans and tomatoes need eight hours. An area near a wall that reflects sunlight can be too warm for some plants.
Container soil can get a lot warmer than the ground. Try shading the containers themselves if they are in a warm spot, while allowing the growing plants to get all the sunlight they need.
Container plants require more frequent watering than plants in the ground, and they also need more frequent fertilizing. Most commercial potting soils include fertilizer to get plants off to a good start. After six weeks or so, start fertilizing every other week with a half-strength liquid fertilizer formulated for vegetables or container plants. Nurseries sell organic and inorganic types. Check label directions for the suggested dilution, then double the recommended amount of water to get a half-strength solution.
For container gardens that are always on view, consider the many vegetables that are ornamental. Look for colorful versions of lettuce or Swiss chard, for example. A combination of leafy lettuces, blooming chives and a viola could produce an instant salad mix in a cool location. For the warm season, try a patio-type tomato with sweet basil at the base. Nurseries often have pots with such pre-planted combinations, but it's fun to create your own.
In April, the options for edibles are almost limitless. You can still start some cool-season vegetables, but it is also planting time for warm-season crops. The Napa Count Master Gardener website has several planting calendars in its “Healthy Garden Tips” section. Find that section under the “Gardening Resources” button on the left side of the home page.
Edible container gardens aren't limited to vegetables. Many perennial herbs do quite well in pots. Try thyme, oregano, marjoram and parsley. Edible flowers such as nasturtiums and violas also thrive in containers. Don't let lack of a garden plot keep you from the pleasure of harvesting your own edibles.
Tomato Plant Sale: U. C. Master Gardeners of Napa County will hold their fourth annual Tomato Sale and Education Day on Saturday, April 23, from 9 a.m. until sold out, in a new location at 1710 Soscol Avenue, Napa. Choose from 28 varieties, including heirlooms and new varieties in a range of colors. These healthy, Master Gardener-grown seedlings include types for fresh eating and for sauce.
Workshops: U. C. Master Gardeners of Napa County will hold a workshop on “Growing Tomatoes” on Sunday, April 10, from 2 p.m. to 4 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. The workshop will focus on techniques for a successful harvest, including soil temperature requirements; tomato types; care and fertilizing; support choices; and integrated pest management. Register with the Parks and Recreation Department at
707-944-8712 or on its web site.
The “Growing Tomatoes” workshop will repeat on Saturday, April 16, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. On-line registration (credit card only); Mail-in/Walk-in registration (cash or check only).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.