Posted on by tonytomeo · 2 Comments

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.

Posted on by tonytomeo · 2 Comments

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.

Posted on by tonytomeo · 7 Comments

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.

Posted on by tonytomeo

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.

Posted on by tonytomeo · 5 Comments

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.

Posted on by tonytomeo · 6 Comments

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.

Posted on by tonytomeo · 9 Comments

New Canes Replace Old Canes

50916thumbHeavenly bamboo, or simply ‘nandina’, is one of those many plants that almost never performs like it should. The intricately lacy foliage is so appealing while plants are young, and changes color with the seasons. The red berries can be comparable to those of holly. Unfortunately, healthy plants grow, and then ultimately get shorn into globs of disfigured leaves and stems.

The same abuse afflicts Oregon grape (mahonia), mock orange (philadelphus), forsythia, lilac, abelia and all sorts of shrubby plants that really should be pruned with more discretion. Their deteriorating older stems should be pruned to the ground as new stems grow up from the roots to replace them. It is actually not as complicated as it seems.

This pruning process, known as ‘alternating canes’, prunes the plants from below. It is a standard pruning technique for maximizing production of blackberries, raspberries and elderberries. It is similar to grooming old stalks from bamboo and giant reed, even if it does not prevent them from spreading laterally.

The deteriorating older stems, or ‘canes’, are easy to distinguish from newer growth. Old canes of Heavenly bamboo and Oregon grape become heavy on top, and flop away from the rest of the foliage. Old canes of mock orange and lilac get gnarled and less prolific with bloom. Aging abelia and forsythia canes become thickets of crowded twigs.

The newer stems are likely a bit lower, but are not so overgrown. Since the foliage is not so crowded, it is displayed on the stems better. Their blooms or berries are more abundant. By the time new growth becomes old growth, there will be more newer growth right below it. In fact, the regular removal of aging canes stimulates growth of new canes.

This is the time to prune Heavenly bamboo and Oregon grape, just because the oldest foliage is as bad as it will get after the warmth of summer. Mock orange, forsythia and lilac should get pruned while dormant through winter, but are commonly pruned just after they finish bloom early in spring. Abelia should probably wait until spring because new growth can look sad through winter.

Posted on by tonytomeo

Indian Summer Is The Norm

70920thumbThe popular definition of ‘Indian summer’ suggests that it is unseasonably warm and dry weather in spring or autumn, and that it typically happens after frost. Well, that definition just does not work here. It makes about as much sense as our so-called drought, which is actually the normal weather for our chaparral climate. Weather that repeats annually is neither unseasonable nor abnormal.

There are certainly years with more or less rain, and years with warmer or cooler weather in late summer and early autumn. Weather is naturally variable. It does not work like the thermostats in our homes, or the automated irrigation systems in our gardens. It is impossible to predict precisely how this summer will end, but it will likely have some characteristics of a normal Indian summer.

The one characteristic of the popular definition of Indian summer that will be notably absent is frost. That will not happen until after autumn. Locally, Indian summer can either be what seems to be a continuation of summer weather, or a resumption of warm summery weather after a bit of cooler weather. The main difference from earlier warm weather is that the nights are significantly cooler.

That is more important than it sounds. We do not notice the cooler nights as much as the plants that are outside all night do. While the days are as warm as they had been, some deciduous plants will begin to defoliate. Eventually, those that get colorful in autumn will begin to do so. Roses can be fertilized one last time, but even as they continue to bloom, they should not be fertilized again.

Indian summer prolongs the summer growing season significantly, but also has the potential to interfere with the winter growing season. Warm days keep warm season vegetables and flowering annuals performing so nicely that we do not want to remove them to relinquish their space for the cool season plants that will be needing it soon! In other climates, frost ends the summer season for us, and necessitates the transition to cool season crops. Indian summer can be too much of a good thing.

Posted on by tonytomeo · 12 Comments

Propagation Is No Big Mystery

Layer_(PSF)All plants propagate. Otherwise, they would go extinct. They all have the potential to propagate by seed or spores. However, some are more efficient at vegetative propagation from stems or roots. Of the later, a few propagate by seed so rarely that it is a wonder that they can evolve, since vegetatively propagated plants are clones, or genetically identical copies, of the original plants.

A single coastal redwood can live for thousands of years. Before such a tree dies, it clones itself by producing adventitious stems from its aging root system. These stems mature into new trees that can live for thousands of years more, only to repeat the process indefinitely. There is no opportunity to generate and share any slight genetic variations that are necessary to natural selection.

Well, this is probably more information than any of us need for our home gardens. It is only relevant to demonstrate than many plants are happy to propagate themselves vegetatively, or are at least conducive to simple vegetative propagation techniques. This is why most nursery plants are grown from cuttings, which are merely pieces of stem stuck into media and forced to grow roots.

For those of us who are not in the nursery industry, there is a more practical way to propagate a few copies of certain favorite plants. Sprawling groundcovers and vines like iceplant, knotweed, jasmine and ivy know all about it. So do many low growing succulents. Their lower stems develop roots where they lay on the ground, and grow into new plants. The process is known as ‘layering’.

Some low shrubby plants that might not layer naturally might be coerced to do so simply by getting a few of their lowest stems buried just below the surface of the soil, with a few inches of the tips sticking up. It helps to scratch off a patch of bark about a third of the way around the buried section of stem, and apply rooting hormone. Sturdy stems can be held down with rocks if necessary.

For most plants, layered stems can be buried about now, left through winter, and should be ready to be separated from the parent plants by next summer, just after any new growth matures. New plants will of course need to be watered generously until they develop enough roots to be self sufficient. Most plants with pliable stems that reach the soil can be layered. Junipers, euonymus, euryops, marguerites, boxwoods and carpet roses are some of the more popular candidates.

Posted on by tonytomeo · 4 Comments

It Will Soon Be Autumn

71004thumbFrom the time they get planted in early spring, tomato plants are expected to perform a bit better than they did earlier in the season. They start out with only a few early tomatoes, but quickly become prolific. Production continues to increase as the plants grow all through summer . . . until now. Newer leaves on top are not staying so far ahead of fading leaves below.

While the weather is still warm, it is difficult to say how tomato plants know that autumn will soon replace summer. They do not seem to be intelligent enough to realize that every day is imperceptibly shorter than the one before. Nor do they seem to be sensitive enough to notice if the nights get slightly cooler. They just know, and they tell all their friends.

If zucchini plants have not started to fade and sag, they will soon. As weather cools, they no longer grow faster than the mildew that they tolerated all summer. Any fruits that are present now should have time to finish developing, but there probably will not be many more after that. (Zucchini fruits are eaten before mature anyway.) Other warm season vegetables are in a similar state.

Acorn, Hubbard, butternut and other winter squash grow through summer just like summer squash do, but are not harvested until the vines wither in autumn and winter. Unlike summer squash that continue to produce many tender juvenile fruit to replace what gets harvested through summer, winter squash plants put all their effort into one or two large ripe fruit.

Warm season vegetable plants still need to be watered as the foliage slowly deteriorates. They only begin to need less water as they lose foliage and the weather gets cooler. They may like to be fertilized one last time, but will not not need it again. Any last phases of corn will stay thirsty later than other vegetable plants because they deteriorate slower, and are rather thirsty anyway.

Seed for broccoli, cauliflower, cabbage, kale and certain other cool season vegetables can be sown in flats or cell packs now so that their seedlings are ready to go when the warm season vegetables relinquish their space in the garden. If space allows, seed for beet, turnip and turnip greens can be sown directly into the garden. Carrot seed should still wait for cooler weather.