Growing Dahlias

Dahlias are among the easier blossoming plants to cultivate in the garden. As natives of Mexico, they thrive in the Monterey Bay area climate and bring drought-tolerance as well.

As mentioned in today’s article about the upcoming sale of the Monterey Bay Dahlia Society, dahlias are available in many different blossom forms and colors and can be a fine addition to the garden.

This column offers basic practices for growing dahlias after you have selected tubers at the Society’s sale.

The first consideration is to select a location will full exposure to the sun and good drainage. Dahlias, like most flowering plants, grow best with six hours of sun each day, and in well-drained soil. Sandy loam is fine, but clay soil will require substantial amendment with organic material.

Dahlia with Bee

Dahlias can be planted any time between the last day of frost (which is not a concern in this area) and as late as mid-June. The local tuber sale is scheduled around the time when last season’s tubers are ready to be dug and divided, so the day of the sale represents a good beginning for the local planting season. If you are not ready to plant, store your new tubers temporarily in a cool, shady environment.

Most dahlias will need staking, so it’s a good practice to position a sturdy stake for each tuber, and to install the stake at the same time that you plant the tune. Inserting a stake later runs the risk of stabbing the tuber.

If you don’t want bare stakes in the garden while the plant develops, you could install a short piece of plastic pipe with the top at ground level next to the tuber, then, when the plant grows to need staking, insert a thin stake (bamboo?) in the plastic pipe and tie the plant to the stake.

Plant the tuber several inches deep, with the “eye” (the growing point) facing up. Some tubers might lack such an eye, and will not sprout, but well-selected tubers will have viable growing points. The eye can be difficult to confirm, so selection can require some experience in identifying tubers that are ready to grow.

Separate the tubers from each other by about two feet.

Protect the sprouting plants from snails and slugs. A good practice is to visit your plants in the night (with a flashlight) or in the early morning to remove any crawling pests that have discovered them. Regular applications of an organic snail control, e.g., Sluggo, also works.

Control flying pests with insecticidal soap or other organic pesticides.

Generally, soil with ample organic content will provide sufficient nutrients for dahlias. If your soil seems “lean,” regular applications of high-nitrogen, organic fertilizer would be helpful.

As each plant grows, tie it to a stake to ensure that it remains upright. The first tie should hold the main stalk loosely to the stake; later ties could connect branches to the stake.

Each branch generally will produce three buds. To produce large blossoms, many gardeners remove two of these buds when they appear. This disbudding process allows the plant to direct nutrients to the remaining bud, with positive effect. If you have several dahlias growing in the garden, you will still have lots o blooms.

At the end of the season, the top growth dies back, and the plant produces several new tubers. The gardener can remove the top growth, and can either dig and replant the tubers or leave them in the ground. In the Monterey Bay area’s moderate climate, dahlias grow quite well when simply left in the ground. After two or three years, they will become crowded and will benefit from dividing.

Enjoy your dahlias! They are wonderful additions to the garden.

Communing with Nature

Good gardening practices almost always equal “working with Nature.” That is simply because natural processes have emerged after many eons as the Earth’s flora and fauna developed strategies for successful survival and propagation.

We write “almost always” from an excess of caution: it would be safe to say “always,” except for the use of the slippery term, “good.” The term “best” would also be debatable.

Still, all gardening practices that are beneficial for air, water, soil, plants and animals turn out to be time-honored, natural practices.

Not surprisingly, these practices are also beneficial to the gardeners, because we are also members of the animal kingdom, and tool-users as well.

Some of the gardener’s benefits are physical: everyone can gain health from exercise that is appropriate to one’s age and ability. Some are economic, providing either an inexpensive form of recreation or, for those with backyard nurseries, supplemental income.

Most benefits, however, are psychological, generating positive feelings, mental peace, and the release of “happy hormones,” e.g., serotonin and dopamine. Admittedly, the latter benefit could be called a physical benefit, but it affects the psyche.

Working with Nature, therefore, works best for gardeners and literally everything in their surroundings. This concept can and should guide the gardener’s response to questions that arise in the garden. “What would Nature do about [insert gardening issue here]?”

This concept also works in reverse. Many commercially motivated gardening practices might appear to save time or increase productivity, but they often create harm in the long run, and sometimes even in the short run.

The worst of these practices involves bringing synthetic chemical fertilizers or pesticides into the garden. Non-toxic, effective organic products are readily available and should always be preferred.

Another avoidable and unnatural practice is the use of power tools in the garden, with gas-powered devices being the most problematic. The most common of these are gas-powered leaf blowers, which contribute faster than cars to climate change and air pollution and disturb the peace that we value in our gardens and neighborhoods.

The usual arguments favoring leaf-blowers include (a) our desire for tidy surroundings and (b) the operator’s interest in making the surroundings tidy as quickly as possible.

We should acknowledge, firstly, that Nature is not tidy. When trees drop their leaves in natural surroundings, the leaves decompose in time and add nutrients to the soil. When trees drop their leaves on pavement, we perceive untidiness. This suggests that we should plant trees only where their leaf drops would be beneficial.

If that is unrealistic (many people like street trees and patio trees), we should use manual methods to remove dropped leaves. Rakes and brooms work quite well, and in capable hands can be as efficient as leaf-blowers, and certainly much easier on the environment and our psyches.

Ken Foster of Terra Nova Landscaping demonstrates an alternative to leaf blowers. Photo by Dan Coryo, Santa Cruz Sentinel

Ken Foster of Terra Nova Landscaping demonstrates an alternative to leaf blowers. Photo by Dan Coryo, Santa Cruz Sentinel

For these reasons, many communities have already banned gas-powered leaf blowers, including Carmel and Santa Barbara to our south, and Palo Alto, Los Altos, and Menlo Park to our north. The Santa Cruz Coalition for a Healthy and Safe Environment (CHASE) has launched a petition favoring a local ordinance to ban these unnecessary and harmful tools. Check it out at http://preview.tinyurl.com/kvgws3d .