A few species of mustard came to naturalize in California, and for a few distinct reasons. Some likely grew first as greens in the gardens of the original Spanish Missions. At least one species also provided culinary and medicinal mustard seed. The more prolific types became cover crops and fodder for livestock. Later in history, mustard seed provided oil.
According to legend, Spanish Missionaries established the route of El Camino Real with mustard. After sporadically dropping seed as they traveled between Missions, they could follow the bright yellow bloom by the next winter, and find greens to eat. El Camino Real became worn enough to navigate before the mustard dispersed too extensively to assist.
Most but not all species of mustard that are naturalized locally are of the genus Brassica. Wild turnip and wild radish provide similar greens, but are generally more likely to bloom pale pink or pale white, rather than bright yellow. Garden varieties of mustard, which are available as seed or in cell packs, provide delightfully tender new leaves with mild flavor.
Vegetable plants are mostly unnaturally productive. Extensive breeding compels them to yield fruits and vegetative parts that are bigger, better and more abundant that what their ancestors produced. Increased production increases their reliance on resources. Without crop rotation, some sorts of vegetable plants noticeably deplete some of what they need.
Rotation, which is the same as crop rotation or garden rotation, is a technique of growing vegetables where different types of vegetables grew previously. In other words, one type of vegetable does not grow in any one place for too long. Some vegetables may produce well in some types of soil for a few years. More consumptive types prefer annual rotation.
This technique disrupts the depletion of particular nutrients that particular types of plants crave. It also allows for replenishment of depleted nutrients in the absences of plants that cause such depletion. Furthermore, some soil borne pathogens find this active cycling to be disruptive. Eventually, plants that cycled out can cycle back into a particular situation.
Tomato plants are particularly consumptive, so appreciate rotation in many types of soils. Eggplant and pepper are related to tomato, so crave many of the same resources, even if they are less consumptive. Therefore, they should not cycle directly into soil relinquished by tomatoes. Unrelated vegetables, such as squash, corn or bean, are more appropriate.
Warm season vegetables that are now returning to the garden might appreciate rotation. A bit of research to determine appropriate placement for them may significantly enhance production. It helps to know which vegetables are related, such as mustard, collard, kale, radish and turnip (of Cruciferae Family), or squash and melon (of Cucubitaceae Family).
Because corn is so high, it should grow to the north of a vegetable garden. Unfortunately, rotation may dictate that it grows to the east for a while, or only in portions of the northern edge that it avoided for a while. Pole beans that like to climb wire fences may sometimes need reassignment to different portions of their fence. Peas should follow their example since they are related.
Like most warm season vegetables, tomatoes, Solanum lycopersicum, are actually seed bearing fruit. They are both the most diverse and the most popular home grown produce. Grape tomatoes are smaller than little grapes. ‘Beefsteak’ can get wider than five inches. Although mostly red, some are yellow, orange, pink, green, brown, purple or pallid white.
The most popular varieties of tomato for home gardens are indeterminate. They produce fruit sporadically throughout the season, on irregularly sprawling stems. Tomato cages or stakes support their growth. Shrubbier determinate varieties seem to be more productive only because all of their fruit develops within a brief season. They work well for canning.
Small tomato plants in cell packs and four inch pots, which are available from nurseries, should grow efficiently in the garden as the weather warms through spring. Varieties that are unavailable as small plants can grow from seed in cold frames through late winter, to be ready for the garden after last frost. Directly sown seed can be vulnerable to mollusks.
Warm season annuals for next spring and summer are already replacing the cool season annuals that bloomed so dutifully since last autumn. As this happens, it is also getting to be about time for warm season vegetables to replace cool season vegetables. Strangely continuous warm daytime weather since December accelerated this process somewhat.
Removal of cool season vegetables that are still productive is as unpleasant as removal of cool season annuals that are still blooming. Fortunately, most cool season vegetables are finished by now, or will be soon. Few linger into warm weather as some cool season annuals might. Regardless, warm season vegetables will need their garden space soon.
Unlike most cool season vegetables, which actually are vegetative, the majority of warm season vegetables are actually fruits. The plants that produce them generally continue to bloom and produce more fruits throughout their respective seasons. Some, such as bush bean and determinate tomato, exhibit brief seasons. Many produce continually until frost.
Therefore, indeterminate tomato, pole bean, squash, cucumber, many varieties of pepper and some varieties of eggplant need no replacement within the same season. Cucumber can get tired enough by early summer to justify replacement in midsummer though. Okra, as well as several varieties of eggplant and pepper, produce for relatively brief seasons.
Phasing prolongs production of warm season vegetables that produce only once or only for a brief season. For example, corn that matures so uniformly that it is ready for harvest simultaneously lasts only a few weeks in a garden. Phases for seeding that repeat every two weeks or so develop in two week cycles. As the first phase finishes, the next begins.
Because so many individual plants are desired, and the seedlings do not transplant well, corn seed prefers direct sowing into the garden. So does seed for bean, root vegetables, and most greens. For tomato, pepper and eggplant, and perhaps cucumber and squash, small plants transplant well, and are not numerous enough in a garden to be expensive. Warm season vegetables grow slowly during cool weather, but accelerate as the weather warms.
Last autumn, it was unpleasant to remove warm season vegetable plants to relinquish space for cool season vegetables, particularly since some still seemed to be productive. Now the cool weather that the cool season vegetables crave will soon be getting warmer. It is still too early for warm season vegetables, but it is time to get ready for them.
If space allows, seed for a quick last phase of certain fast growing cool season vegetables can be sown. Radishes, carrots and beets still have time to mature before the weather gets too warm, although the beets will be the small tender sort. There probably is not enough time to grow big beets for canning. Leafy lettuces can still be sown to replace what might be running out early. Large vegetable plants like broccoli, cauliflower and cabbage grow too slowly to mature before spring weather gets too warm, so will need to wait until next autumn.
Peas are odd vegetables that like to grow in autumn and spring, in between warm and cool (or cool and warm) season vegetables. The first phase of peas can be sown now, and followed by subsequent phases every two weeks or so until the weather gets too warm for them.
Even though it will soon be getting too warm for cool season vegetables, it is not yet warm enough to sow seed for warm season vegetables directly into the garden. Fast growing vegetable plants that get sown directly, such as beans, corn and most squash, will need to wait until the weather is warm enough for them to grow efficiently, and the cool season vegetables finish and get out of their way. However, seed for vegetable plants that can get planted as seedlings, such as tomatoes, peppers and eggplants, can be sown into flats or cell packs in greenhouses or cold frames.
Tomato, pepper and eggplant seed sown directly into the garden when the weather gets warmer will be more likely to get eaten by snails or succumb to rot as they germinate than seedlings that got an early start in a greenhouse or cold frame (although snails and rot are not problems in every garden). For those who do not want to start growing seedlings at home now, seedlings will certainly be available in nurseries when it is time to put them out into the garden. However, the advantage to growing them at home is that there are many more varieties of seed available from catalogs and online than any nursery could stock with seedlings.
Tropical plants are clueless. They do not understand that autumn is just prior to winter, when the weather may get uncomfortably cool. Philodendron selloum continues to develop fresh new leaves that mature slowly in cool autumn weather, and may consequently lack resiliency to frost in winter. Vegetable plants and flowering annuals are not so ignorant, which is why so many that were productive through summer are nearly finished, and some are ready to relinquish their space to cool season counterparts.
Like the many warm season vegetables, most of the cool season vegetables should be grown from seed sown directly into the garden. Only those that produce efficiently from fewer but substantial plants, like broccoli, cauliflower, cabbage, Brussels sprout and some of the heading lettuces, can be grown practically from seedlings purchased in cell packs. Because individual plants produce only once, more can be added to the garden in phases every two to four weeks through the season to prolong production.
Chard, kale and collard greens can likewise be grown from cell pack seedlings if only a few plants to harvest as intact heads or large leaf greens are desired. However, a package of seed costs about as much as a single cell pack of only six seedlings, but contains enough seed for many more mature heads, as well as for abundant production of ‘baby’ greens plucked from many juvenile plants through the entire season. Those to be harvested as heads should be planted in phases with enough space to mature. Those that will get plucked through the season can be sown or planted once early in the season, and perhaps followed by a second phase if productions starts to diminish.
Root vegetables, such as beet, carrot, turnip and radish, really do not recover well from transplanting from cell packs. Individual cells are sometimes crowded with too many seedlings that must push away from each other as they mature. Otherwise, if not crowded, each cell contains only a few seedlings that are not nearly as practical as simply sown seed would be.
Although each individual root vegetable plant produces only once, they all mature at different rates, so most types can be sown in only one or two phases instead of several phases every two to four weeks. If the biggest get pulled first, the smaller ones continue to mature. They are less perishable than other vegetables, so any abundance is not likely to be wasted.
There are three practical ways to grow onions. They are most popularly grown from seed or from ‘baby’ onions known as onion sets. The third and sneakier way to grow them is from separated cell pack seedlings. Cell packs typically contain too many onion seedlings that would develop into crowded clumps anyway. There are often as many seedlings as could be grown from a package of seed!
Peas get sown as seed early in autumn to grow and produce before winter gets too cold. Another phase can be sown as winter ends for spring production.
Plants notice it before people do. They respond accordingly. Vegetative growth slows or stops completely. Most remaining bloom does likewise. Fruit and seed finish developing. Less fresh produce is available from the garden. Boston ivy and Japanese maples might already be changing color. They all know that the days are shorter and nights are cooler.
Warm season produce gets less abundant as summer ends because most is fruit, which contain seed. Most plants naturally finish with seed production prior to autumn. Most cool season produce is truly vegetative and lacking seed. It naturally grows during autumn or winter, with the (‘fruitless’) intention of blooming and fruiting during the following season.
It seems as if warm season vegetables were replacing cool season vegetables from last winter only a few months ago. Perhaps they were. That process began about half a year ago, but never completely stops. Various phases of various vegetables start and finish at various times. Now, some warm season vegetables might continue to produce until frost.
Corn is of those warm season vegetables that remain productive. Seed for the last phase would not have been too late if it got into the garden two weeks ago, but will take time to produce. Broccoli seed sown at the about same time could be the first of the cool season vegetables in the garden. However, it is likely more practical to plant seedlings a bit later.
Seed for cabbage and cauliflower can go into the garden now. Alternatively, it should do as well in flats or cell packs, for later planting. This procedure delays their occupation of garden space, which might still be occupied by late warm season produce. Besides, it is easier to defend tiny seedlings in flats or cell packs from slugs, snails, birds and insects.
For big and leafy cool season produce, it may be more practical to purchase seedlings in cell packs rather seed. Since only a few seedlings of each type are needed, they are not too much more expensive than seed. However, confinement to cell packs disfigures root vegetables, such as beets and carrots. Their seed can get into the garden in two weeks to a month.
It is safe to say that any remaining frost damage can be pruned away. Frosted foliage and stems were only left through winter to help insulate inner stems from more damage by subsequent frost, and to avoid stimulating new growth that would be even more sensitive to frost. Now that there is no threat of subsequent frost, and surviving but damaged plants are growing anyway, there is no reason to retain unsightly frosted foliage. The few plants that do not regenerate probably did not survive.
Spring is the busiest time of year for most plants. By now, most have either bloomed or will be blooming soon. Early spring bulbs have already finished. Later bulbs will be blooming soon enough. Deciduous plants that were bare through winter are developing new foliage. Evergreen plants are likewise growing new foliage to replace older foliage that will get shed later in the year.
If necessary, flowering cherry, flowering crabapple, lilac, forsythia and mock orange (Philadelphus) can be pruned as they finish bloom. Flowering cherry should not need much; but flowering crabapple might be in need of aggressive structural pruning. Some of the older canes of lilac, forsythia and mock orange can be pruned to the ground, where their replacement canes are probably already emerging.
Overgrown or disfigured oleander, photinia, bottlebrush, privet, pittosporum and juniper that need restorative pruning can be pruned now. They recover most efficiently in early spring, and have plenty of time to develop plenty of new growth before they slow down again next autumn. If pruned much earlier, they would have stayed bare longer, since they would not have grown much through winter. Besides, almost all pittosporum are susceptible to disease if fresh pruning wounds are exposed to rainy weather.
Seed can be sown for any of the warm season vegetables and flowering annuals, such as zucchini, corn, okra, nasturtium, lupine and sunflower. Tomato, pepper, eggplant, petunia, marigold and busy Lizzie (Impatiens) can likewise be grown from seed, but are easier to grow from small cell pack plants. Cuttings of jade plant, iceplant, sedum and all sorts of succulents, as well as divided pups of aloe, agave and yucca, really get going well this time of year.
Winter squash grow through summer. This includes spaghetti squash, Cucurbita pepo subspecies pepo. They thrive with warmth, rich soil and steady watering, to mature in late summer or autumn. They store nicely through winter. Technically, spaghetti squash can ripen earlier in summer. However, flavor improves with a bit of age. Mature fruits can stay on their vines until the foliage gets crispy at the end of the season.
Spaghetti squash fruits resemble melons. Most types get about four inches wide and eight inches long. Color ranges through creamy white, pale tan, yellow and golden orange. Fruits with pale color tend to have milder flavor. After cooking, the otherwise solid flesh pulls apart into squiggly bits that resemble spaghetti. The big seeds within may not be true to type. Related squash hybridize freely, particularly with zucchini.
The long vines of spaghetti squash can be somewhat sloppy. This can actually be an advantage. Such vines can sneak about into otherwise unused areas, like pumpkin vines. Alternatively, they might like to climb trellises or shrubbery. They are happy to grow from mounds too, and wrap around the perimeters. Fruits on the ground benefit from occasional turning. Superfluous and fruitless male flowers are good for frying.
Certain parts of the vegetable garden are ideal for certain types of vegetables. Wire fences are perfect for pole beans to climb. Corn belongs at the northern edge where it will not shade lower plants. Vegetable gardening would be simpler if it were like permanent landscaping. Instead, vegetable plants are seasonal and very consumptive. They prefer fresh resources. Garden rotation gives them more of what they crave.
Garden rotation, or crop rotation, is growing vegetables where they have not grown recently. For the most efficiently planned gardens, it happens seasonally. Alternatively, some types of vegetables might be happy to grow repeatedly in the same soil for a few years. Some vegetable plants are more consumptive than others. Some soils are more susceptible to nutrient depletion than others. A few variables are involved.
Furthermore, the various vegetable plants deplete distinct sets of nutrients. Conversely, they allow other nutrients to replenish. That is why garden rotation is so effective. For example, if beans grow in the same location for too long, they deplete their favorite nutrients. The nutrients that they use less of secretly replenish. Tomatoes or corn might appreciate the replenishment, without craving so much of what is deficient.
Eventually, vegetable plants can return to a location where they grew a few years earlier. Again, a few variables are involved. Some might return after an absence of only a single year. Consumptive plants, such as tomatoes and beans, should avoid a previously used location for three or more years. So should related vegetables. Peppers and eggplants are related to tomatoes, so should avoid the same used locations.
Garden rotation can also inhibit proliferation of some soil borne pathogens. In other regions, this is a more serious concern. Soil borne pathogens that infest mildly during their first year might flourish with the same host material during a second year. Garden rotation deprives them of that.