Vegetables Come And Vegetables Go

61012thumbVegetables are annuals too, just like the flowering bedding plants that get replaced seasonally. Some are technically biennials, and a few might even have the potential to be short term perennials if they ever got the chance. Yet, for the purposes of home vegetable gardens, the warm season vegetables that produced through summer should now get replaced with cool season vegetables.

Yes, pulling up tomato plants to make room for cabbage is the same dilemma as pulling up petunias to make room for pansies. No one wants to do it while the plants are still productive. Tomato plants might continue to make a few more tomatoes until frost. Yet, planting cool season vegetables should not be delayed for too long. They want to disperse their roots while the soil is still warm.

Just like warm season vegetables, many of the cool season vegetables are more efficiently grown from seed sown directly into the garden. Root vegetables like beet, carrot, radish and turnip do not recover well from transplanting. Besides, cell packs do not contain many seedlings, even if multiple seedlings within individual cells are divided. It is more practical to sow seed evenly in rows.

Baby greens can also be grown from seed because so many small plants are wanted. Unlike heading lettuce that get harvested as individual mature plants, baby greens get plucked as they develop, from plants that may never reach maturity. Chard, kale and collard greens grow well from seed, or can optionally be grown from cell pack seedlings if fewer larger leaves are preferred.

Broccoli, cauliflower, cabbage and Brussels sprout are more typically grown from cell pack seedlings because only a few individual plants are desired. One or two six packs of cabbage might be more than one garden needs, and do not cost much more than a packet of seed. They mature at different rates, so larger ones can be harvested first, while smaller ones get more time to mature.

The root vegetables work the same way, maturing somewhat variably through a few weeks. However, secondary phases planted a few weeks after primary phases can start to mature as the primary phases get depleted. ‘Cole’ crops such as broccoli, cauliflower, cabbage and Brussels sprouts, consume the same resources, so perform best in small groups with a bit of separation.

Winter Dormancy Begins In Autumn

50923thumbAutumn is for planting . . . but not much else. While it is important to get certain new plants into the garden before cool and rainy weather, other gardening chores will not be necessary while plants are becoming less active before winter dormancy. Raking falling leaves is probably the biggest of the new chores that are specific to autumn.

Formal hedges that have been getting shorn regularly since spring may not need to be shorn again until next spring. They simply will not grow much between now and then. If possible, pittosporum and photinia should not be shorn once the weather gets rainy. Their freshly cut stems are more susceptible to certain diseases while wet than during dry weather.

Citrus and tropical plants should not be pruned late because pruning stimulates fresh new growth that will be susceptible to frost later in winter. Even if tender new foliage does not get frozen, it can get discolored and disfigured by cold weather. Cool weather inhibits vascular activity necessary to sustain the development of healthy new foliage anyway.

For the same few reasons, fertilizer will not be necessary later in autumn. Fertilizer can potentially stimulate new growth when it is not necessarily wanted. Also, some nutrients in fertilizer are less soluble (or chemically unavailable) while the weather is cool. Only plants that grow through winter, like cool season annuals, vegetables and grasses, will want fertilizer.

Planting is done in autumn because plants are either dormant or less active than they had been during warmer weather. They can take their time to disperse their roots into comfortably cool and damp soil. Evergreen plants do not draw as much moisture from their roots while foliage is cool and damp. Deciduous plants draw even less moisture without foliage.

Spring blooming bulbs get planted in autumn not only so that they can disperse their roots leisurely, but also because they need to get chilled to bloom well. Bulbs can be phased, so that those planted earlier will bloom before those of the same kind planted later. However, if planted too late, they may not get sufficient chill.

Take It Slowly In Autumn

81010thumbNo more fertilizer! . . . almost. The main exception is turf that might need a bit of fertilizer if it must stay green through the coldest part of winter, but that is another topic for later. Otherwise, most plants start to go dormant through autumn, and should be as dormant as they get by the middle of winter. Fertilizer later than now could be as logical as espresso just before trying to get to sleep.

Keeping marginally frost sensitive plants up past their bedtime can have serious consequences. Lemon trees are not often damaged by frost in the mild winter weather here. That is because they stop growing through late summer, and the last of their new foliage matures before autumn. Fertilizer applied too late can stimulate late new growth, which is more likely to be damaged by frost.

Plants that like a last application of fertilizer as late as the end of September, such as roses, use it for their last minute preparations for dormancy. It actually takes a bit of effort to abscise (shed) foliage. Besides, healthy foliage is easier to abscise than distressed foliage is. Well fed roots, although significantly subdued by dormancy, work later into winter, and get an earlier start in spring.

Roses are, of course, not as likely to be damaged by late application of fertilizer as lemon trees are. They know better than lemon trees do about what to do when the weather gets cool. They just go dormant. Much of the extra nutrients get ignored as they leach through the soil with winter rain. Many of the nutrients become insoluble and unavailable to plants as winter weather gets cooler.

Autumn is the season for allowing most plants to slow down and get ready for winter dormancy. Trying to get them to be as green and productive as they were in spring can do more harm than good. Only plants that are active through winter, such as cool season vegetables, cool season annuals, and some types of turf, might appreciate moderate applications of fertilizer. If newly installed plants want fertilizer, they should get only enough to keep them happy until they get more next spring.

Fireblight Kills Pears And Apples

61005thumbBunches of blackened leaves hanging from blackened stems in otherwise healthy pear trees really are as serious as they look. They probably appeared as new growth was developing in spring, and are still as dead now as they were then. As surrounding foliage colors and falls, the blackened foliage will remain until it gets knocked out by rain and wind in winter, or until it gets pruned out.

Because these dead bits seem to have been scorched by fire, the bacterial infection that causes them is known as ‘fireblight’. Pear, flowering pear and evergreen pear are most susceptible to it. Apple, flowering crabapple, quince, flowering quince, hawthorn, loquat, cotoneaster, pyracantha and photinia are also very susceptible. Some cultivars are more resistant to fireblight than others. Few other members of the ‘rose family’ are rarely infected.

At the base of each dead bit (or toward the supporting limb from dead bits that do not stand upright) is a lesion where the bacteria that cause fireblight infected the stem. These infections not only obstruct vascular activity and kill the distal (outward) portion of the infected stems, but they also spread proximally (inward) to more important limbs, branch unions and even main trunks and roots.

Fireblight is transmitted mostly by bees, and also by other insects, birds, rain and wind, while trees are blooming in spring. It most often infects through flowers, and can also infect where infected debris, particularly falling flower parts, get caught in branch unions. If it infects root suckers, it can infect the roots right away, and kill an entire tree. Root suckers should be pruned away anyway.

There is no remedy for fireblight. Because it is very contagious, all infection should be pruned out. Because infection extends inward from obvious lesions, infected stems should be pruned back at least a foot and a half below (inward from) obvious infection. Sadly, this often disfigures infected trees, sometimes severely. Pruning scraps should be removed from around susceptible trees.

Some say that fireblight should be pruned out in summer. Others say that winter is best. Really though, the only bad time is spring, while weather is warm but still damp, and the trees that are so susceptible to fireblight are active and blooming. The reason for pruning it out in winter is that the disease is inactive while cold. However, it does not get cold enough here to slow it down much.

Annuals Change With The Seasons

50930thumbLike it or not, the warm season annuals that were so flashy all through spring and summer will eventually need to be replaced with cool season annuals to provide color through winter. It is always unpleasant to pull up the annuals of a previous season while they are still blooming, even if they are already getting scruffy and discolored. It is actually easier if they got roasted by recent warmth.

Some warm season annuals last longer than others. Many are actually perennials that can be overplanted with new cool season annuals as they get cut back or go dormant through their ‘off’ season. Some cur back perennials may not survive through winter; but those that do can regenerate next spring, just as the cool season annuals that obscured them all winter are finishing.

Wax begonias, for example, are warm season annuals that can continue to bloom until they get frosted. Where sheltered from frost, they only need to be cut back because partial defoliation exposes knobby bare stems. If they can be hidden by pansies or violas through their bare phase, they never need to be removed, and some will be happy to regenerate in spring.

Conversely, cyclamen, sweet William, chrysanthemum and some primroses are cool season annuals that have the potential to survive under the lush growth of warm season annuals next summer; but that is a topic for later. (Some people are allergic to primroses like poison oak.) Iceland poppy and ornamental cabbage and kale are not so perennial, but are quite colorful through winter.

Alyssum and nasturtium really are annuals that do not survive much more than one year. However, they can perform through summer where sheltered from heat, or through winter where sheltered from cold. In ideal situations, their self sown seedling replace deteriorating older plants, so that they can perform throughout the year. Nasturtium should be planted as seed, not from cell packs.

Calendula is a popular cool season annual early in the season, but may not last through the end of winter. Yet it is popular because it is so excellent through autumn. Chrysanthemums are even flashier, although they are often replaced as soon their first bloom phase finishes.

Leaves Are Starting To Fall

81003thumbAutumn is slow in getting here. Yes, as of last Sunday, it is now autumn. The date is determined by the equinox, so is the same for everyone in the Northern Hemisphere, and is the same for the arrival of spring in the Southern Hemisphere. It just takes a bit longer for autumn weather to develop in the mild climate here. Nights are cooler. Shorter days are not as warm as they had been.

Even without the pretty foliar color that cooling weather prompts in other regions, deciduous foliage is already beginning to fall. Poplars, willows and some other trees that a naturally endemic to riparian environments are the first to start. Some are actually developing a slight bit of color, mostly soft yellow. More colorful foliage needs cooler weather, so will develop as weather gets cooler.

Sooner or later, falling leaves will need to be raked from lawns and groundcover. Trees that drop their leaves for a long time through autumn and into winter necessitate more frequent raking, even if their leaves do not accumulate enough to do much damage. Trees that drop their leaves within a shorter season can quickly drop enough to shade out turf or groundcover, or cause them to rot.

Because fallen leaves can stain hardscape surfaces, they should be raked efficiently from pavement and decking as well. Those of us who do not mind the staining, or even appreciate its rustic patina, might leave some of the fallen foliage out for a while, but should not leave it out long enough to promote rot in decking. Some leaves cause staining quite quickly, especially if wet from rain.

If leaves need to be raked from the garden and pavement, they probably need to be cleaned from roof gutters and anywhere else they accumulate on roofs. Just like raking, the clearing of fallen leaves from gutters and roofs is scheduled around the timing of the falling leaves, although it is not nearly as frequent. It may even be unnecessary if trees are too far from roofs for their leaves to fall or be blown onto them. Leaves that stay in gutters too long eventually decompose and clog downspouts.

Early Autumn Color Might Disappoint

60928thumbIt might seem like autumn color is a bit early this year. In the wild, where there is no irrigation, native box elders, and maybe some of the cottonwoods and sycamores, are already yellowing. The box elders are already dropping some of their foliage. However, this is not caused by an early chill. It is caused by late warmth after an otherwise mild summer, and might inhibit better color later.

It is still impossible to say for certain. There are so many variables that affect autumn color, such as temperature, humidity and daylength. Some of the plants that develop color late, like flowering pear trees in irrigated landscapes, might not be bothered too much by the same variables that are troubling wild box elders now. Where autumn weather is so mild, color is unpredictable anyway.

Sudden cool weather after mild weather late in summer would have been better for autumn color. (Warmth through the middle of summer is no problem.) Foliage lingers best if the weather stays cool without getting too cold. Wind and rain will eventually dislodge foliage. Sheltered sweetgums might hold their foliage until just before it gets replaced by new foliage late in the following winter.

The earliest trees to color, as well as those that are notoriously less reliable for color, are the most likely to be inhibited by the weather this year. Besides box elders, cottonwoods and sycamores, other marginally colorful trees like willows, walnuts, maples, elms, redbuds, smoke trees and deciduous oaks, may develop bland color. Mulberries and tulip trees, though early, are more reliable.

Sweetgums (which are also known as liquidambars) , flowering pears, Chinese pistaches and maidenhair trees (which are also known as gingkos) are the most reliable trees for color locally. Maidenhair trees turn remarkably bright yellow. The others can be various shades of bright yellow, orange, red or burgundy red, (although Chinese pistaches do not not often get burgundy color here). Crape myrtles have the potential for the same color range if conditions are right.

Leaves Are Starting To Fall

50923thumbAutumn color is different every year. Sometimes, early and sudden cool weather after a mild summer promotes good foliar color that lingers longer while relaxed trees slowly realize that they should probably start to defoliate. Sometimes, early wind and rain accelerate defoliation of otherwise good color. There are a few variables that trees must adapt their performance to.

Warm and arid weather two weeks ago started the process of defoliation suddenly and a maybe slightly early this year. Even before the weather gets cool, deciduous trees are already starting to shed the oldest of their foliage that they do not need in order to hold their youngest foliage a bit later into autumn. Evergreen trees do the same to limit desiccation.

Slightly breezy weather that was so pleasant after such heat was just enough to start dislodging deteriorating foliage. Now, leaves are already starting to fall before they develop much color. Redwoods and pines are likewise dropping browned needles. Fortunately, trees that are the most colorful in autumn tend to hold their foliage better until the weather gets cooler.

It is impossible to predict how colorful trees will be this autumn; although if storms are as healthy as predicted, the mild temperatures may inhibit color, while wind and rain dislodge colorful foliage. Regardless, it is already time to start raking falling leaves and needles. They can get messy, and when the rain starts, they can stain pavement and clog gutters.

When more foliage falls later in autumn, it will need to be raked from ground cover, surviving portions of lawn, and any other plants that collect it, so that it does not shade out the sunlight.

Cool Season Vegetables Are Coming

80926thumbIt is getting close to one of those two unpleasant times of year for the vegetable garden. It happened last spring, and it will happen again this autumn. Plants that so dutifully produced vegetables through the last season must relinquish their space for plants that will produce vegetables for the next season. In autumn, it will be cool season vegetables that replace warm season vegetables.

They are all on their own distinct schedule. Pulling up corn stalks is not so distressing because we know when they are finished. Pole beans, bell peppers and summer squash might make it easy as well, if they start to look shabby as their season ends. Tomatoes are the more unpleasant ones to pull up, since they can continue to produce right up to the end, even as the nights get cooler.

If they were planted on the edge of the vegetable garden, and allowed to grow outside of the space needed for incoming cool season vegetables, winter squash can stay until their vines succumb to frost. Fruits that get harvested just prior to frost last better in the cellar. Those exposed to a bit of frost attain better flavor. Winter squash really are summer vegetables. They just finish in autumn.

Seed for beets, carrots and various root vegetables that are grown this time of year should be sown directly into the garden. Root vegetables do not transplant well. Besides, too many relatively expensive seedlings would be needed to grow a substantial quantity of such vegetables. Seed should be sown in phases every few weeks so all the vegetables do not mature at the same time.

Peas, spinach and leafy (non-heading) lettuces should likewise be grown from seed sown directly into the garden. However, it is more practical to grow broccoli, cauliflower and cabbage from seedlings rather than seed. Because only a few plants of each are needed, they are not terribly more expensive than seed. One or two six packs might suffice. Another option that is useful for those who grow varieties that are unavailable in nurseries, is to grow seedlings from seed in small pots or flats, to plant out later.

Start Cool Season Annuals Early

30925Twice a year, it becomes necessary to discuss the unpleasantries of pulling up the flowering annuals (as well as vegetable plants) of one season, to relinquish space for those of the next season. Just a few months ago, cool season annuals got replaced with warm season annuals. Now, those same warm season annuals will get replaced with cool season annuals for the next few months.

It is unpleasant because the outgoing annuals are probably still blooming when it is time for them to go. It might be easier to wait for cool season annuals to get roasted by hot weather, or for warm season annuals to get frosted. Unfortunately, by that time, the incoming annuals would be at a disadvantage. Hot or cold weather is also uncomfortable for plants that are not yet established.

Sure, warm season annuals like warmth, but only after they have sufficiently dispersed their roots to sustain their growth during warm weather. This is most efficiently accomplished while the weather is still mild earlier within their season. Cool season annuals likewise do not mind cool weather, but do not grow as well as they do during the warmer weather earlier within their season.

This is why it is better to plant pansy, viola, sweet William, Iceland poppy, stock, calendula and the various primroses earlier rather than later if possible. There is no exact science here. A forecast for warm weather certainly justifies delay. Cyclamen and ornamental cabbage and kale are a bit more sensitive to warmth, so could wait a bit longer. They grow well through cold weather anyway.

Chrysanthemum, alyssum and nasturtium are odd ones. Chrysanthemum, although perennial, is most often planted as a short term autumn annual while it is already blooming or is just about to bloom. It rarely gets a second chance if it finishes bloom before winter. Alyssum and nasturtium can be both warm and cool season annuals. They only gets replanted this time of year because individual plants perform through one season or the other, but probably not both. Nasturtium should be grown from seed.