Editor’s note: Marlene Simon is the staff horticulturalist at the UC Davis Botanical Conservatory, where she grows and cares for over 4,000 species of the world’s most exotic plants and flowers. Her column will appear biweekly.
By the time spring comes around and you are coveting your neighbor’s daffodils and tulips, it is already too late to grow your own bouquet. Fall is the time to plant spring blooming bulbs. First off, some terminology (simplified, for a short column): “Bulb” is the layman’s term for geophyte, which are underground energy storage structures of the plant. Common examples of bulbs are tulips, daffodils, alliums, amaryllis, hyacinths and lilies. There are countless numbers more.
One main rule of planting bulbs is knowing which have a chilling requirement. Chilling simply means putting the bulbs in the refrigerator for eight to 12 weeks before planting. Remember to CHILL, not FREEZE. I hear too often from people who have put their bulbs in the freezer and killed them. You want to avoid storing fruit by your bulbs, because certain fruits — such as apples — give off the ripening gas ethylene, which can cause bulbs to flower early or kill off the potential buds.
It’s important to know which bulbs require chilling in our climate (USDA Zone 9b) in order for them to bloom. Luckily, our winters are cold enough for nearly all bulbs to bloom year after year without having to chill in the refrigerator. The exceptions are tulips and hyacinths.
▪ Most tulips are treated as annuals in our area because they require a greater number of days below 40 degrees.
▪ An outlier are Darwin Hybrid tulips. You can plant them in the Sacramento area and they will come up every year.
▪ For all other tulips, you need to dig up the bulbs, chill them and replant.
▪ Similarly, when you purchase tulip bulbs from a nursery, you have to chill them before planting.
These are a unique case. They require chilling after they are purchased from the nursery, however, in the Sacramento region, they will then bloom on their own in following years without digging up bulbs and chilling.
When it comes to planting bulbs, adding bone meal to the bottom of the hole you dig is a standard gardening practice. This is the gardening version of a 401k investment because the bone meal will not be utilized for first-year growth, as bulbs are energy stores that travel with everything they need for their first year. The bone meal — which is a good source of phosphorus — will aid in the following years of flowering.
California Native and Perennials
Fall is the time to plant perennials and California native plants. Why? These plants need to have established root systems by the time we get our first extended period of heat. Otherwise, the heat stress and desiccation will compromise growth. The one exception to this are frost-sensitive plants (such as citrus and more tropical plants like bananas). If not established by the time frost comes around, they run the risk of dying.
Winter and fall vegetable planting comes fast and furious. Seeds of many winter vegetables such as broccoli, cauliflower and Brussels sprouts should be started in August. This is always a challenge for me, as most of us are not thinking about winter in August (except dreaming of cooler temps). Don’t fret if you dropped the ball on August planting because many of the winter vegetables can be planted in October without worry. There are too many to list here, but the Sacramento Master Gardeners have a wonderful chart to show what vegetables to plant and when. Check it out at sacmg.ucanr.edu.
One of the mandatory winter crops that I need to mention are fava beans. Having married into a Portuguese family, I’m “required” to plant these, and a rivalry has ensued between my father-in-law and me as to who can grow the biggest and best beans. Besides being delicious, they are a great way to add nitrogen to your soil. Fava beans — like many plants in the legume family — use bacteria to convert one form of nitrogen into a form utilized by plants.
A quick note on protection from birds. I hate bird netting. It is so hard to work with, as it gets tangled incredibly easy. It has caused me to go into fits several times in the garden. I have found the perfect defense against birds attacking my emerging seedlings is to cover the soil with overturned nursery flats (the plastic trays plants come in, normally six-packs). They are far easier to lay down and pick back up than bird netting.
Ask The Plant Lady
I get a common question from Sacramento area residents at this time of year: Why are my Japanese maples getting burnt leaf edges? Don’t worry, this is perfectly normal for many deciduous trees — it is a sign of aging that occurs in the fall. Lacy leaf varieties of Japanese maples seem to suffer more. Excess salts and fertilizers can also cause burnt leaf tips. A potential way of combating this condition is adding soil sulfur in spring and fall. Sulfur will drop the pH of soil allow boron —a common salt in the area — to be mobile and flush out during heavy rains and deep soaking.
What’s your question for The Plant Lady? Send her an email at firstname.lastname@example.org and she’ll have an answer for you.