By Susanne von Rosenberg, UC Master Gardener of Napa County
For spring cheer, few flowers are better than daffodils or, more correctly, Narcissus. When I first planted a bunch of Narcissus in my front yard, neighbors started calling my house the happy house.
While it's best to plant spring-flowering bulbs in the fall (November in our climate), it's not too late to plant them now. They will flower later in the spring, and you'll need to irrigate longer. Next year they'll flower on their normal schedule.
There are about 40 species of daffodils. All are in the genus Narcissus, which in turn is part of the Amaryllis family. Naming of daffodils can sometimes create confusion, as they can be referred to as daffodils, jonquils and narcissus. Both daffodils and jonquils are in the genus Narcissus, but jonquils and daffodils are different species. Unlike daffodils, jonquils are usually scented. They always have yellow hue and multiple flowers on a hollow stem.
The paperwhites that are easy for us to grow here in Napa Valley are yet another species of Narcissus: tazettas. Bulbs catalogs will often refer to jonquils and tazettas as daffodils, but this is botanically incorrect. While these are different species of Narcissus, their planting and cultivation needs are the same.
Narcissus are some of the easiest bulbs to grow. There are more than 32,000 registered cultivars, ranging from two inches to about two feet in height. The smaller cultivars are referred to as miniatures. There are early-, mid- and late-season cultivars. With proper planning, you can have flowering Narcissus for about two months. You can also grow history. The American Daffodil Society lists several still-available cultivars that originated in the 17th and 18th centuries.
In addition to their cheery color, Narcissus score points because most critters leave them alone and they are relatively drought resistant. The bulbs and foliage are mildly poisonous, and rodents (including gophers and squirrels) and deer do not eat them. However, slugs and snails appreciate the flowers and bulbs and can even start eating the bulbs before they break ground.
Narcissus naturalize easily. Naturalizing requires only soil with adequate drainage, sufficient space and time to allow the bulbs to multiply. The American Daffodil Society provides recommendations for the best cultivars for naturalizing. Narcissus can be naturalized under deciduous trees; they will usually bloom with just morning or afternoon sun. Narcissus look best in clumps rather than rows. I've read that you can simply toss handfuls of bulbs onto the planting area and then plant them where they fall.
Plant Narcissus bulbs twice as deep as their diameter. The top of a 2-inch bulb should be 4 inches below the ground. Space the clusters at least three times the diameter of the bulb. Most planting guidelines recommend a minimum of 5 or 6 bulbs per cluster. Following this recommendation, one square foot of planting area will require 10 to 12 bulbs.
Dig some low-nitrogen fertilizer into the soil at planting time, and then fertilize again lightly when the first green shoots emerge, when the bulbs flower, and in the fall when rain begins. Keep the bulbs moist after planting and water as needed to keep the soil moist until the foliage naturally turns yellow.
The blooms on Narcissus die back long before the foliage. The foliage provides food to the bulb to enable it to flower the following year. The leaves can look ragged in the garden; I have mine in a bed with wildflowers, and the wildflowers and their foliage cover up or distract from the unsightly leaves.
Problems with Narcissus include bulbs failing to flower due to excess nitrogen fertilizer or lack of sun, and buds withering without ever blooming, a condition known as bud blast. Weather, nutrition and cultivation practices can all cause bud blast. Extreme hot or cold weather after bloom can cause bud blast in the following year's flowers. Bulbs planted in shallow holes are more prone to bud blast.
Cutting foliage too soon will reduce the amount of food the bulb can store and may also cause bud blast the following year. The other cause of bud blast is inadequate water. As long as the plants are growing (fall through May or June), you need to keep the soil moist. I once planted bulbs in late fall in anticipation of winter rain that never came, and I had fairly extensive bud blast the following spring.
Control slugs and snails by handpicking them (after dark or early in the morning are the best times to catch them), or by applying an iron phosphate-based bait. These baits cause the slugs and snails to stop feeding and are non-toxic to birds and mammals (including humans). If you handpick the slugs and snails, give them to a friend with chickens. Chickens love them.
Have fun planting some smiles!
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- 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.
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