By Denise Seghesio Levine, UC Master Gardener of Napa County
Reading about nasturtiums always confused me. Nasturtiums were described as easy to grow and “almost foolproof.” I tried starting them several times to no avail, and yet apparently everyone else knew the secret. This was borne out when my daughter-in-law planted several patches of nasturtium seeds in our garden and growing boxes and they grew. Seemingly easily.
Nasturtium (Tropaeolum minor) is an annual with peppery leaves and spicy flowers. You can find a variety of sizes ranging from tidy eight-inch mounding types to climbing or cascading varieties that can reach five feet in height. Unlike most lush summer plants that appreciate compost-rich soil with plenty of humus, nasturtiums will provide a much more luxurious show of colorful blossoms in sparse soil. Fertile soil will give you lush green foliage, but you will miss the pops of color that make nasturtiums such a bright addition to the garden.
Nasturtiums are pretty, edible and protective, and they generously self-sow if they find their happy place. So it's worth the effort to get them going, and with Napa Valley weather just now finally warming, you still have plenty of time to get nasturtium seeds in the ground.
Plant nasturtium seeds one inch deep and about ten inches apart. You can plant in clusters of three and thin out all but the strongest seedling or take your chances and plant them singly where they will remain. Most of them will likely come up. Some gardeners like to soak nasturtium seeds before planting to speed germination. If you do, remember to soak them no longer than eight hours to avoid losing your seed to rot.
Nasturtiums like sandy, well-draining soil without too many nutrients, but they do like ample water. If you have planted them in beds, let them dry out a bit between each watering. Nasturtiums planted in pots seem to need watering more often than those planted in the ground and will appreciate a little dilute fish emulsion occasionally to replace the nutrients that frequent watering leeches out. Every site is different, so pay attention to how your plants are doing. In my garden I have noticed that the plants that volunteer appear to be the most efficient water users.
Nasturtiums have rounded leaves with deep veins radiating from the center. They produce wide, deep-throated single or double flowers in oranges, yellows, creamy whites, maroons and reds. Nasturtiums are pollinator magnets and act as feeding stations for long-proboscis birds and insect nectar seekers. The leaves provide landing pads for a variety of other winged creatures.
Nasturtiums are butterfly host plants, attractive to many varieties as places to lay their eggs. Butterflies will lay their next brood's eggs often on the underside of nasturtium leaves, but sometimes on the top, hopefully hidden from predators. In about 14 days the larva will emerge, turning into caterpillars eating little holes in your garden's leaves.
One of my earliest memories of working at the Master Gardener Help Desk was taking a call from someone who had planted a butterfly garden but had no butterflies. A minute later she told me the other problem she had with her garden that year was an “infestation” of caterpillars, which she had finally eradicated. Unfortunately, those caterpillars would have been her butterflies.
Therein lies a very important lesson: Do not kill the caterpillars if you want butterflies.
But how can you tell which caterpillars are butterflies and which are just eating your cabbage and nasturtiums? The website Gardens With Wings (www.gardenswithwings.com) has a tool to help identify the butterflies in your garden. Pick the main wing color of the butterfly flitting around your garden and click on the tab. Up pop pictures of many butterflies. When you see your butterfly, you can see what its eggs look like and what the larva and eventually identifiable caterpillars will look like. It is a fun, useful tool that will help you learn to love caterpillars and to tend, nurture and support our fragile butterfly populations.
Nasturtiums can work in a variety of garden spots from partial shade to full sun. They also act as host plants for aphids, luring them away from your roses, kale and other brassica and cabbage crops. Most plants appreciate having nasturtiums around.
Nasturtiums do really well in our Mediterranean climate. Considered a summer annual, my volunteer nasturtiums were still blooming in December last year and were up and blooming again of their own volition by early May. Now when people ask me if I grow nasturtiums, I tell them, “Sure, they are easy!”
Next workshop: “Succulents Celebration!” on Saturday, July 20, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Learn why succulents have become the trendiest members of the plant kingdom. 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.
What do the blue chicory flowers blooming in meadows and vineyards, the pansies in your window box and the honey-scented blossoms on your lemon tree have in common? You can eat them.
A stroll around your winter garden, nearby vineyard or neighborhood might reveal surprising edible flowers to cheer, nourish, flavor and decorate winter plates.
But just because blossoms are pretty does not mean you can eat them. Some flowers are poisonous. Identify any flowers you plan to eat or serve and make sure no sprays or chemicals have been used on them.
By the time you read this, nasturtiums (Tropaeolum majus) may be gone, but in early December the blossoms in navel-orange, taxi-yellow and vermillion blossoms are still flourishing at the edges of my garden. The honey-tinged heat and color of nasturtium blossoms provide contrast in citrus salads and in salads with deep-green arugula or miners' lettuce. Both the petals and the leaves have a peppery flavor, making a milder garnish for guests who don't like spice.
Calendulas (Calendula officinalis) look like bright, full daisies in a palette of pale yellow, apricot and bright orange. They grow through most of our Napa Valley winters. Calendula is an annual and generously self-sows every year, so leave a flower or two to go to seed. After the first rains, expanding circles of little calendula seedlings are already greening up the areas in my garden where calendulas grew last year. In a few months, their neon-orange flowers will be the first to bloom in profusion as winter turns to spring.
Calendula petals may be sprinkled in salads, ice cream, soups or risotto. If you have several plants to choose from, taste to see which you prefer.
All members of the viola family are edible and bloom bravely through all but the iciest weather. Fresh-faced pansies, fragrant violets (Violata odorata) and blue and yellow Johnny-jump-ups don't just provide vivid color for garden beds and pots. They also contribute blossoms for confetti-colored butter logs to melt on biscuits. Or arrange them in two-dimensional bouquets to decorate special desserts.
With blue or white star-shaped blossoms, borage (Borago officinalis) can grow in shady spots. Its cucumber-flavored blossoms can be frozen in ice cubes or used to garnish salads or sorbet.
Herb blossoms are all edible, so consider using the delicate white flowers on lemon verbena and perky chives as well as peach, pear, plum and almond blossoms.
Always check to make sure flowers are edible. While you might think fragrant sweet pea (Lathyrus odoratus) blossoms should be edible, they are not. This kind of sweet pea is poisonous and should be eaten with your eyes only.
On the other hand, sugar snap peas, shelling peasand other edible peas have blossoms and shoots that can be safely consumed. Eating pea blossoms is for those who spurn delayed gratification and live for the moment, or for those who do not like to eat their peas. On the other hand, gardeners who hope to ultimately harvest peas will have to forgo all but the first blossoms.
Citrus blossoms are edible, but taste them to make sure you like the flavor. Some are bitter. As a general rule, the sweeter the fragrance, the sweeter the flavor. Use blossoms to infuse cream for ice cream or whipped cream or use to scent lemonade.
All types of dianthus are edible, including ‘Sweet William' blossoms, carnations and pinks. Ranging in color from pure white to almost black, dianthus blossoms give artistic cooks many beautiful colors to choose from. Taste the flowers and remove the bottom white part of the petal if it seems bitter. Steep in syrups or mix into butters. Frost cakes, then lay a stencil over the cake and sprinkle shredded flower petals to fill the outline.
Edible flowers can expand your kitchen choices. Check this site https://whatscookingamerica.net/EdibleFlowers/EdibleFlowersMain.htm for a list of edible flowers. Tulips, begonias,chrysanthemums and gladiolas can make surprising contributions your meals. Learn which flowers are safe to eat and teach your children well.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Rose Pruning” on Saturday, January 7, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Certified rosarian Lynne Andresen and other Master Gardener rose enthusiasts will demonstrate and explain proper pruning techniques and review rose types, common rose disorders and routine maintenance. Online registration (credit card only); Mail-in registration (check only or drop off cash payment).
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.