March Garden Tips and Vegetable Planting Guide

As a small child, each year I would find in my Christmas stocking, a fresh orange, which was a special treat to be looked forward to amid the English winter. Now living in California there I still experience that delight in picking fresh navel oranges from a home garden tree to eat or juice. At this time of year citrus is available in abundance in California.

The history of the navel orange -

Citrus mutates easily. It was known by growers that citrus would produce fruit with different characteristics, number of seeds, sweetness, thickness of skin, on different limbs. The navel orange variety was noticed on a single limb on a tree grown at a monastery in Bhai, Brazil in the early 1800s. This single limb was used to clone trees to produce the tasty, seedless navel with which we are so familiar.

How did the navel orange come to California?

In the early 1800s the navel orange was propagated by bud grafts onto root stock. Several young navel trees were sent from Brazil to William Saunders at the USDA which had been created by legislation signed by Abraham Lincoln on May 15, 1862. Lincoln called USDA "The People's Department” for its projected future work on food, agriculture, economic development, science, natural resource conservation and other issues.

Eliza Tibbets and her husband, Washington, D.C. neighbors of William Saunders, moved to the new Riverside Colony, California about 1870 and Eliza requested some navel orange trees as the Riverside climate seemed ideal for citrus growing. Two navel trees, shipped across the country from Washington, D.C., planted by Eliza produced their first fruit around 1875, and became very popular locally. As neighbors and those in the citrus industry tried the Tibbets' navel orange and wanted to grow them, the Tibbetts sold bud grafts to local nurseries. From these two initial trees the CA navel orange industry exploded. One of the original two trees still survives in Riverside, California. The California navel orange won both the gold and silver medals at the World's Industrial and Cotton Centennial in New Orleans in 1885

Why does the navel orange have a navel?

The genetics of the mutation for navel oranges produces a secondary flower. This secondary flower leads to the development of the sometimes-seen smaller segments of orange within an orange and also the characteristic navel.

Why do some seedless navel oranges have seeds?

This is due to the occasional cross pollination of the navel orange flower by a nearby seeded variety of orange. The seeds do not produce a navel orange tree and often when grown produce thorny nonproductive plants.

Now is a great time to add citrus to your home garden. The Citrus Calendar will guide you as to when each type of citrus produces fruit so you can choose and plant your favorites.

For tips on successful citrus growing in our area, read UC Master Gardeners of Sacramento County article Growing Citrus in Sacramento.

One very important thing to be aware of is the citrus greening disease which is spread by the Asian Citrus Psyllid. Do not transport fruit or plants outside our region. Currently the disease is only present in southern California where the California Department of Food and Agriculture (CFDA) has an intensive eradication and quarantine program. The map to the right indicates the southern California quarantine zones. For more information, visit the UC IPM webpage on Asian Citrus Psyllid.

Enjoy growing some California gold!

March Tips

General maintenance

With the February rains and the warming temperatures mosquitoes are emerging to lay eggs in any standing water – even a capful of standing water. The life cycle for the mosquito is egg, larvae, pupa to adult, with the egg, larval and pupal stages taking place in water. Male mosquitoes have short lifespans and do not consume blood from birds or mammals. The female mosquito needs a ‘blood meal' to produce eggs.

West Nile Virus causes a disease that can affect birds and mammals (humans) and is present in Yolo County. The virus is transmitted through the ‘bite' of an infected mosquito. Over three hundred species of birds, have been affected by West Nile Virus since it was first detected in 1999. Crows, jays and magpies are particularly susceptible to the West Nile Virus. In humans the disease may be mild with no sign of symptoms but in some cases serious neurological effects develop.

The primary mosquito species that carries West Nile Virus in Yolo County is the Culex tarsalis and it can fly up to two miles. The life cycle is about seven to ten days from egg to emerged adult. The female lays from one hundred to three hundred eggs with each deposit. It is important to stay alert even after a short spring shower and remove any standing water so that mosquitoes do not establish a breeding ground.

How you can help

If you find a sick or dead bird report it to health officials by calling (877) 968-2473 or report it online at the California Department of Public Health's Report a Dead Bird webpage where there is Information on how to safely handle the bird and report the bird's location. Health officials may pick up the bird for testing. Information on dead birds and the county program of trapping and testing mosquitoes allows health officials to monitor the prevalence of West Nile Virus.

For more information check the Yolo County News webpage.

Weeds

This is the season for weeds, get ‘em young and get ‘em often, is always the best approach. Weeds such as convolulus and Bermuda grass have root systems that provide a store of energy deep underground (convolulus to 20 feet, Bermuda to almost four feet). Persistence in removing each small shoot found will result in the underground roots not being replenished. Overtime an infestation can be controlled but vigilance is the key. Removing any weed before it produces seed will reduce the ‘weed seed bank' in the soil.

Fruits

As the weather warms flower buds break, do not use dormant oil spray. After bud break the spray can damage foliage or bloom and affect beneficial insects and pollinators.

If your dormant pruning is not complete wait until after the fruit has cropped and summer prune to shape and control a tree's growth. Support any extended or weak branches to prevent breakage. Wait until the summer to prune apricots and cherries.* Pruning cuts provide a path for fungal and bacterial diseases carried in rain and moist atmosphere to infect apricots and cherries.

Ornamentals and annuals

Finish any remaining rose pruning and feed roses to encourage growth and bloom. An application of alfalfa pellets around roses can stimulate new growth. Alfalfa is the equivalent of a general fertilizer of 5-1-2, giving a source of nitrogen, calcium, iron, magnesium, phosphorus, zinc, also triaconatol, which is a fatty acid growth stimulant.

This is prime planting season, almost any plant that suits our climate can be planted at this time. Local sales and nurseries will be well stocked. Look for CA natives or plants originating from a Mediterranean climate which is similar to our Yolo County climate.

Start seeds of zinnias, cosmos, calendula, marigold, petunia, tithonia, celosia, scabiosa, globe amaranth, nicotiana, and sunflower for summer color.

Bulbs, Corms, and Rhizomes

Fertilizer

Most plants will benefit from a spring application of compost or fertilizer. Always check the labels before applying. Excess nitrogen in the soil will encourage leaf growth rather than fruit or bloom.

Pest control

Spring is when both beneficial insects, and insects we regard as pests emerge. A daily walk around the garden to observe, especially early morning or evening, will allow you to notice and take care of any beginning infestations. A strong spray from a garden hose can reduce or solve aphid or spittle bug problems. Slugs and snails are more easily seen at night, hand picking, beer traps, or an application of iron phosphate will help reduce the population. Iron phosphate is safe for use around pets and wildlife.

For more information on identifying pests and the least toxic solutions to pest problems go to the UC IPM Home, garden, turf, and landscape pests webpage.

Vegetables

March is the beginning of the transition to summer crops in the vegetable garden. Some cooler weather crops such as beets and carrots can be planted but if there are above average temperatures in April and May these may bolt. Tomatoes, peppers and eggplant can be started in pots inside or a greenhouse and will be ready for transplanting when the soil has warmed. Annual vegetables depend on day length, moisture, air temperature and soil temperature to produce well. Check weather forecasts and soil temperatures to adjust planting and transplanting dates accordingly. Cooler than usual – wait for the soil to warm, warmer than usual - shade plantings or wait until cooler. For more information on optimum soil temperatures see UC ANR's Soil Temperature Conditions for Vegetable Seed Germination.

References

*The Stanislaus Sprout (Jan. 15, 2019) Wait, Don't Prune Apricot or Cherry Trees Just Yet!

**US Food and Drug Administration (Sept. 16, 2021) Lovely Lilies and Curious Cats: A Dangerous Combination