How deep and wide should the planting hole be?

A: The planting hole should be as deep as the distance from the bottom of the pot to its soil level. If the hole is dug deeper and refilled, the loosened soil beneath the plant will subside and the plant’s crown will be lower than the surrounding soil. This condition is a common cause of plant failure.

Digging the hole wider than the pot and roughing its sides makes it easier for the plant’s roots to grow into the surrounding soil.

Late Spring in the Southern California Native Garden

The wildflowers were spectacular this year. They are still blooming in the high desert, but in my garden most are past their peak. The poppies, tidy tips and gilias are going to seed, but it was quite a show!

Taking my dog, Milo, out for his walk, I start thinking about the rhythm of the southern California native garden. It is mid-spring and while my neighbors are busy mowing, watering and fertilizing their ever-needy lawns, I am thinking about what I will do next.

Tidy up

Tending a native plant garden is particularly interesting because the work varies throughout the year. No endless cycle of mowing, watering, fertilizing, mowing, watering.…… Instead I cast an eye on the annuals, so colorful and eye catching two weeks ago. I collect their seeds to share with my gardening buddies and pull out the now messy plants. The poppies I treat differently. I remove some and cut others to the ground, allowing them at least one more display this year.

Once I remove the annual wildflowers, I can see the weeds that were struggling to compete with them. Most are annuals and I can ignore them since they have already done what I prefer to prevent – set seed for their reappearance next year. I take them out anyway, just to tidy up the garden. Of course, eliminating those that have not yet seeded gives me particular satisfaction since I know that removing one now may prevent 20 new weeds from coming up next year.

Mulch

To complete the process of tidying up the garden, I go to my compost heap and dig a little way down to extract partially decomposed leaves. This rich material - a deep glistening brown, as fragrant and fresh as spring - is spread in the space between the shrubs and trees that the wildflowers had occupied just days ago. I am careful to keep it away from the plant stems since I don’t want to encourage rot in this sensitive area. The mulch reduces weeds, enriches the soil and gives the garden the “cared for” look so important for any garden, native or not.

Pinch back

Once the annuals have been removed I turn my attention to the perennials and shrubs. The monkeyflower and sage are sending out long shoots which I pinch back about an inch or two to a leaf node. This results in a tighter, bushier plant with copious blooms. I move on to the ceanothus that I planted in November and do the same. I will continue this process, especially during and right after these plants bloom. When in bloom, pinching back provides lovely bouquets for my house while extending the flowering period. With flowers, it is often the case that the more you cut the more you get. So bring your partner a lovely bouquet and enhance your garden.

Can I plant anything now?

It is spring and between mowing, watering and fertilizing, my neighbors are busy putting in summer annuals. Most California natives do best if planted in the late fall to early winter, but as an immigrant from the east coast, it is hard for me go through the spring without planting something. The plants that I bought at the Rancho Santa Ana Botanic Garden Spring Plant Sale during the first Saturday in April are all in the ground, but I yearn to plant more, especially in the space opened up by the removal of the wildflowers.

Luckily one can always plant something here in southern California. Your chances of success with woody shrubs and trees are greatly reduced at this time of the year. You will have more luck with perennials and plants that require year around water. Since my garden is not heavily irrigated in the summer, I limit myself to coral bells, penstemons, yarrow and deer grass. They fill in the garden nicely.

Water

It is raining today and we are edging closer to record rainfall for the year. Walking in the light rain I see many sprinklers adding even more water to home landscapes. I am reminded that even in rainy years we cannot afford to waste this precious resource (visit the bewaterwise.com website by Metropolitan Water District of Southern California). Still, when and how much to water is a big question for home gardeners. For native gardens, it is often important to provide supplemental water during dry winters. This is the time of year chaparral and scrubland plants are actively growing. It was unnecessary to water this winter, but if the rains do stop, watering during the spring, before the plants have entered their dormant period, will extend their growing season. You need to check your plants often. Get to know them so that you can tell when they are slowing down for the long, hot summer. As the heat sets in and your plants stop growing, taper off the water. Watering during the summer encourages disease and unsustainable growth. Summertime in southern California is perfect for soft gray colors, slow growth, less physical work and the spicy smell of sage and sagebrush. Get ready to sit back and relax.

Seasons

I feel a surprising melancholy as I remove the last of the wildflowers. Three months ago the anticipation of this year’s colorful display was almost unbearable. Next year I will extend the annual wildflower season in my garden with plants that bloom into late spring and early summer. The rich pink of farewell-to-spring appear in May and June, as the name suggests. Yellow daisies called madia also provide late season color, and the poppies I cut back now will give me color through May, June and maybe even July.

Looking over my garden it feels like autumn in the East. Just as I used to look forward to winter as a time of subdued color and reduced outdoor activity, I now take a long, deep breath in anticipation of a slower season. When I first arrived in California I had a hard time distinguishing seasons, now I find that they are as obvious as the autumn foliage and winter snows of the east coast.

It Is So Hot! Do I Water or Not?

It is a very hot day. As I sit down to write this article on summer garden care, I decide to check the temperature. It is 4 PM and currently 93 degrees Fahrenheit. Something on the weather website (www.weather.com) catches my eye. There is a watering needs index that states that we are currently at a “Very High Watering Need.” The legend explains “It is very dry and watering is necessary.” This recommendation is based on temperature and precipitation, and indeed, it is hot and dry! The underlying assumption is that our gardens are populated with plants that grow actively in the warm season. This is true for much of the country, but it is not the case for many native plant gardens here in California.

Summer in southern California is similar to the winter in the rest of the country. Colors are subdued and plants are slowing down, even going dormant. This is an adaptation to our long, dry season. To make it through the more than six months with no rain and high temperatures plants have developed many other adaptations too, including waxy leaves to reduce water loss, white hairs to reflect sunlight and capture fog and dew, and extensive root systems. Some plants are annuals that complete their life cycle in one year, producing seeds in the spring that await more hospitable conditions to germinate and begin again.

As the heat turns on and California native plants slow down, so should your watering. During a plant’s first few years in your garden, anywhere from one to three, you must check it often. Water it enough to keep it going, since its root system is not fully developed, yet not so much that it puts on unsustainable, excess growth or succumbs to fungal and bacterial diseases. As your garden matures, it requires less attention. Depending on your plant choices, areas with established plants can be watered about once a month or less during the summer. Some plants like flannel bush (Fremontodendron species), should get no summer water at all.

Because conditions vary from garden to garden, and even within gardens, the best irrigation schedule is determined by watching your plants. In my garden, I manually set each zone on the controller. Beds with new plants receive water approximately once a week, although this depends entirely on how they look. If they are drooping and the soil near their roots is dry, I water them, making sure that the entire root system gets wet. New plants placed among established natives are watered by hand, as needed.

Walking through the garden in the late afternoon heat, I am tempted to water a four year old black sage, but I remind myself that it is hot and tired, and it does not want a shower.

What are California native plants?

Tree mallow budCalifornia native plants may be defined as those species that would have been found in California before Europeans arrived. When specifying native plants for a region we must be clear about the exact geographic limits. For example, plants native to northern California may or may not be native to our area. This distinction becomes especially important when we are trying to restore native habitat, or are planting in or near natural, open space. We do not want to risk introducing plants that might alter existing plant populations. [See O’Brien, Bart, The Intersection of Conservation and Gardening: An Overview of the Consequences of Growing California Native Plants, Fremontia, Vol. 29, No. 1, p. 15. January 2001.] Home gardens, away from open space, streams or creeks, have considerably more latitude, though choosing plants from similar geography and habitats will make caring for the garden much easier. It is, however, important to avoid invasive species (see question #4) that can spread over large areas.