Houseplants Might Enjoy Some Weather

80404thumbThey were not always houseplants. They came from somewhere else. Most came from shady tropical forests, which is why they have such big dark green leaves, and are so tolerant of shady home interiors. They are pretty good sports about tolerating the domestic lifestyles that we subject them to, but they would really prefer to be thousands of miles away, growing wild back home.

Home interiors lack the sort of weather that the natural environments of houseplants get. The majority of houseplants would prefer rain, humidity, occasional breezes and perhaps more warmth. Some succulents may not miss the rain, but might crave heat and more sunlight. Regardless of what houseplants want, that can not get all of it in the comfort of our homes. They want to get out!

Unfortunately, that is not an option. Plants that have adapted to the relative darkness and protection from (shortwave or SUV) ultraviolet light in the home would roast if suddenly exposed to direct sunlight. (Windows block SUV light.) They would get battered by wind and damaged or killed by frost in winter. Those that become outdoor plants should be transitioned slowly and methodically.

However, there are a few times a year when the weather is not expected to get too cold, hot or windy, when houseplants can come out to the garden to get very lightly rinsed with a hose. Taking them out immediately prior to a light rain is even better. Rain is gentler and more sustained than a brief and coarse hose rinsing. Both techniques rinse away dust and residue from insect activity.

Rinsing does not eliminate mite, scale or mealybug infestations, but temporarily eliminates the residue from such infestations, and somewhat disrupts their activity. Mites prefer dusty plants to clean ones. While plant are outside, it would be a good time for any necessary repotting, or to apply horticultural oil to control mites or scale. Mineral deposits can also be scrubbed from saucers and the bottoms of pots. If hosed during sunny weather, houseplants should be shaded by a larger tree or awning.

Autumn Really Was For Planting

70531thumbIt is easy to see why there are optimum times to prune, and just as easy to see when pruning should not be done. Generally, deciduous plants prefer to get pruned while dormant and bare. They should not be pruned when actively blooming or making new foliage. Roots are of course not so easy to see. Do we really know what they are doing, or what sort of mischief they are getting into?

Autumn is the best time for planting most plants. They are less active than they had been earlier in the year, and many are going dormant. Either way, they do not need much. Once in the ground, their roots are kept cool and moist by the weather. They get to sit there all winter, as they slowly begin to disperse their roots to get ready for the following spring. It all fits into their natural life cycle.

Shopping habits, however, do not. By autumn, many plants are neither as pretty nor as tempting as they were earlier in the year. By winter, the weather keeps many of us inside, and out of nurseries. Now that it is spring, it is difficult to resist all the pretty plants that are blooming so delightfully. We are tempted to buy them compulsively, even if we have no immediate plans for them.

That is okay. We can make this work. Buying certain plants in bloom actually has certain advantages. It shows how and when particular plants bloom. This might be helpful when trying to decide between different cultivars of deciduous magnolias, flowering cherries, flowering crabapples or wisterias, for example. Besides, they will finish blooming quickly, and start to produce new foliage.

If planted before new foliage matures, new plants should be planted in cool weather, and maybe sprayed lightly with water after the roots get soaked in. This is best for drought tolerant plants like ceanothus, that want out of their cans (nursery pots) as soon as possible. If new plants stay in their cans long enough for foliage to mature, they must be watered carefully, but not kept saturated. The black vinyl cans should be shaded, since they get warm in sunlight.

Frost Is History For Now

80328thumbThere is no doubt that frost will return next autumn. It does that every year. Right now, we are more concerned that is should not return prior to that. It is now safe to plant plants that are sensitive to frost. Even if the weather were to somehow get cold enough to necessitate protection of frost sensitive plants, it will not be severely cold, and it will not last long. It is best to start now than to delay.

It is also safe to prune away foliage and stems that were damaged by frost through winter. It was best to leave it in place through winter, both to provide a bit of insulation for undamaged stems below, and to not promote new growth. Pruning it away allows warming sunlight to the undamaged stems, and stimulates generation of new growth. A bit of new growth might already be apparent.

Many leafy perennials can be cut to the ground, or at least just above their rhizomes. The tall vertical canes of cannas can be cut back to the low horizontal rhizomes that creep along the ground. The canes are not really stems anyway, but are merely upright foliar shoots. Any shorter new shoots that are beginning to develop can remain, even if a few outer leaves happen to be damaged.

Zonal geraniums can likewise be pruned almost to the ground, leaving only stubs of lower stems, even if only upper and outer foliage was damaged by frost. Although they do not need to be cut back so severely, they respond to such pruning splendidly, with vigorous new stems and foliage. The fungal foliar disease known as ‘rust’ overwinters in old leaves that get removed in the process.

Lemons, limes and any other citrus that were damaged by frost only need to have their damaged stems removed as far back as viable growth, where new buds might already be visible. However, if more pruning is necessary, this would be a good time to do it. Major pruning should not be done later in summer because the sensitive bark of inner stems can be scalded by sudden exposure to too much sunlight. Small trees that are sensitive to frost become more resilient as the grow larger.

Weeds Have Been Very Busy

60323They are weeds for a reason. They grow like . . . well, weeds! By definition, they are unwanted. Yet, they typically proliferate and grow faster than desirable plants. They aggressively compete for space, sunlight and resources. Many weeds start to grow through winter, and get established while other seedlings are just beginning to germinate, or other plants are just waking from dormancy.

Besides staying ahead of other plants, weeds stay ahead of us by growing so much while the wintry weather keeps us inside. Many weeds are really just trying to stay ahead of insects or animals that eat them in the wild. Since almost all weeds are exotic (nonnative) and far from their natural homes, the insects or animals that should eat them are not here to do so. It is an unfair advantage.

Now that the weather is more conducive to gardening, weeds should be pulled as soon as they are big enough to get a grip on. This includes tree, shrub and big perennial weeds like blue gum eucalyptus, Acacia dealbata, coast live oak, glossy privet and giant reed. If simply cut down, they will regenerate even stronger, and will probably need to be dug out. The roots are difficult to kill.

Annual weeds are very different. They will die by next winter without any help. Some will die when they dry out over summer. However, they should be pulled anyway, before they bloom and sow their seed. If the weeds are too abundant to exterminate, they should at least be cut down before their seed develops. In some situations, the mown or cut weeds might be preferable to bare soil.

Burrclover, bindweed and purslane stay so low to the ground that mowing or cutting weeds does not slow them down much. They must unfortunately be pulled, which is a serious chore in large areas! Dandelion and foxtail can get mown once, but they have a sneaky way of coming back lower to avoid losing seed the next time. Dandelion can actually come back next year as a perennial.

Bermudagrass and crabgrass are low growing perennial grasses that spread vegetatively (with their stems), even if deprived of their seed. They are very tough! Spurge and oxalis seem like they should be wimpy, but they sow seed so profusely and so early that, by the time they get noticed, their next generations are already started. Oxalis survives winter with perennials stems and bulbs.60323thumb

Warm Season Vegetables Start Now

P80312The calendar does not always agree with the weather. It really is about time to start replacing aging cool season vegetable plants with fresh new warm season vegetable plants. Earlier warm and dry weather had suggested that it was getting late. More recent frosty weather followed by rain suggested otherwise. Regardless, there is no point in arguing with what the calendar determines.

The last seedlings for broccoli, cauliflower, cabbage and Brussels sprouts (for those who are able to grow them) should be well established in the garden. There should be enough cool weather for them to finish before the heat of summer causes them to go bitter. No more should be planted this late. Also, the last seed for beets should have been sown already. Peas should finish soon.

Warm season vegetables like tomato, pepper, squash, cucumber, corn and bean are the main concern now. Tomato and pepper are most easily planted as seedlings purchased in cell packs. A packet of seed costs as much as a cell pack, but must be sown and grown into seedlings, which is extra work. If necessary, varieties that are unavailable in cell packs can be grown from seed.

The other warm season vegetables grow so fast from seed that there is no advantage to planting them as seedlings here. Some would be distressed from transplant as seedlings. Besides, so many individual plants of each type are typically grown together that it would be expensive to purchase so many cell packs. Squash might be an exception if only a few plants would be enough.

Bush beans may seem like they would be easier to grow than pole beans because they do not require support. However, pole beans can grow on the sunny side of a fence in the background of a vegetable garden, utilizing otherwise useless space. If it would not damage the fence, string can be strung in a zigzag pattern (up and down) between nails pounded part way into the top and bottom of the fence. If the string is held an inch or so from the fence (at the heads of the protruding nails), bean vines would be happy to climb it.

Spring Blossoms Precede Summer Fruit

00407

Cherry blossoms are such an excellent tradition in Washington D.C., as well as in Japanese neighborhoods of the West Coast. ‘Kwanzan’ and ‘Akebono’ flowering cherries in Japantown of San Jose are glorious when they bloom early in spring. They are less common but just as spectacular in Los Angeles. More varieties grow in the cooler climates of Sacramento, Portland and Seattle.

Yet, after all the work the trees put into bloom, they produce no fruit. These prettiest of the cherry blossoms are sterile. They are known as ‘flowering’ cherries, which is a polite way of saying that they are ‘fruitless’. Cherry trees that produce fruit are very similar and bloom about as profusely, but do so with somewhat more subdued utilitarian flowers. After all, they have to work for a living.

Many of the deciduous fruit trees have ‘flowering’ counterparts that are grown for their showy flowers. Purple leaf plums, which are really flowering plums that happen to have purplish or bronze foliage, are the most popular because the foliage is so colorful after bloom. Flowering nectarines and flowering peaches are rare, but not as rare as flowering apricots and flowering almonds are.

Flowering crabapples are the counterparts to the entire fruiting apple group. They are not really sterile, so produce tiny fruits that mostly get eaten by birds. Flowering pears, which are commonly known as ‘ornamental’ pears, are grown more for their impressive autumn foliar color than for their potentially modest bloom. They also produce tiny fruits. The evergreen pear lacks autumn color. Flowering quince is an odd one. It is not even the same genus as fruiting quince.

Fruit trees bloom too. They may not be as colorful, but their simpler and paler blossoms are about as profuse as those of their flowering counterparts. Their stems are usually straighter and more vigorous because they are pruned for fruit production instead of allowed to develop naturally. A few stems can be left unpruned to be cut and brought in as cut flowers when they eventually bloom.

Whether flowering or fruiting, almonds and plums should bloom before pears and apples. There is no guarantee though. Weather can delay early bloomers, or accelerate late bloomers. Earlier frost promoted healthy bloom, but the subsequent abundance of rain is unfortunately ruining flowers that are blooming now. For fruiting trees, this means that much or all of the fruit will be ruined.00414

Potted Plants Going To Pot

80314thumbIt seems like such a waste that so many of the prettiest blooming plants are generally regarded as temporary. They are grown in the most synthetic of environments, forced into bloom, sold at their prime, and kept as potted plants just long enough to finish their bloom cycle. When their bloom deteriorates, they typically get discarded, or planted out into the garden where they rarely survive.

Poinsettias epitomize these flowering potted plants, which are known in the nursery industry simply as pot plants. Almost all of us have given or received them as gifts or decorated our home with them prior to Christmas. Although they are not considered to be annuals, few survive as houseplants, and almost none survive in the garden. No one wants to admit to what happens to the rest.

Okay, so it is not really a big loss. Poinsettias do not do well here anyway; and even if they survive, they are not as appealing in the landscape as they are as pot plants. What about all the others? Easter lilies, chrysanthemums, amaryllis, hydrangeas, orchids, azaleas, miniature roses, kalanchoes and even a few evergreens and living Christmas trees are all grown as forced potted plants.

It is important to be aware that all of these forced plants were grown in very synthetic environments, in which temperature, humidity and perhaps even day length were manipulated to coerce the plants to bloom, or for evergreens to be as lush as they are. Some were stunted with growth regulators. Recovering from such manipulation takes some time and effort, but for most, it is possible.

Of course, they all have their own personalities, and require different sorts of pampering. Some only need their old flowers to be pruned away, and will be able to produce new foliage that is adapted to their new environment. Amaryllis starts out without foliage, so has the advantage of making all new foliage after bloom. Chrysanthemum will eventually want to be cut back to favor new basal foliage. Easter lily foliage should be left while it dies back slowly until dormancy. New foliage grows next year.

Rain Makes Watering Seem Obsolete

IMG_1921Watering has not been much of a concern lately. All the rain has kept our gardens too wet to work in. Some of us have been more concerned with erosion caused by runoff. Automated irrigation systems are probably disabled until the rain stops. Soil can drain somewhat between rain, but will not really dry out until the weather gets warm again. Dormant plants do not draw much moisture.

However, as strange as it may seem, there are a few plants that might want to be watered. Potted plants on roofed porches are sheltered from rain, just like houseplants. They will not dry out nearly as quickly as they would during warm summer weather, but they do eventually get dry if not occasionally watered. Hanging pots and small pots containing big plants typically dry out faster.

Plants that were moved onto porches for shelter from frost can be moved out into the rain if that would be easier than watering them. It is very unlikely that they will be damaged by frost this late. Besides, as long as it is raining, the weather can not get cold enough for frost. (In fact, any frost damage that was left through winter can be pruned away now that fresh new growth is developing.)

Small plants in the ground under big eaves might need to be watered as well, if they have not been in the ground long enough to disperse their roots beyond the eaves. Annuals do not last that long. Mature plants might have dispersed their roots well enough to get enough moisture from outside. They might not notice if the soil inside is too dry, as long as the weather is cool and humid.

Houseplants are of course in a league of their own, and as long as they are inside the home, get no water from rain. They might need less watering in winter if the home stays cooler; or they might need slightly more watering if the home heating system reduces humidity. Regardless, some might enjoy going outside to a spot sheltered from the wind, for a brief rinse from a mild rain shower.

Eventually, the weather will get warmer and drier, and automated irrigation systems will need to be reactivated. When that happens, the emitters and sprinklers should be checked for efficient function. While inactive over winter, they can get grungy or clogged with mineral deposits. Plants will not need much water early in the season. Irrigation increases as spring and summer progress.

Plants Are Masters Of Deception

80307thumbMany of us already understand that daisies, sunflowers, asters and all related flowers are composite flowers, which bloom as many tiny flowers clustered tightly together to form what appears to be significantly larger single flowers. Distended ‘ray’ florets around the edges imitate petals that other types of flowers are equipped with. It is like one stop shopping for pollinators craving nectar.

Many other plants have developed comparably ingenious techniques for facilitating what they need to do. Flowers are the more common beneficiaries of their creativity. Fruits, leaves, stems and roots have also been modified out of necessity. For example, the colorful bracts around tiny poinsettia and bougainvillea flowers are modified leaves that pretend to be petals to attract pollinators.

We think of strawberries, pineapples and figs as fruit. Strawberry fruits are actually the small specks on the outside that resemble seeds. The sweet and juicy part that suspends these fruits is a modified stem. Each ‘eye’ of a pineapple is a swollen flower, that is fused with flowers around it. Tiny fig flowers bloom and produce seed all within the fleshy floral structure that is eaten like fruit.

Some types of acacia trees have no real leaves. Their foliage is comprised of distended petioles (leaf stems) known as ‘phyllodes’, but without the leaves that petioles normally support. Juvenile leaves that actually look like lacy acacia leaves do not last long. Makrut lime has big phyllodes too, but in conjunction with leaves, which is why they seem to have double leaves joined end to end.

Cacti and the euphorbs (poinsettia relatives) that resemble them are among the most deceptive of plants. Euphorbs that have both recognizable leaves and thorns provide hints about how they work, since some tufts of thorns and spines also have leaves. Each tuft is a node. Small bristly spines are modified leaves. Larger and stouter thorns are modified axillary stems. A few stems develop into limbs or segments. Without leaves, the fleshy green stems do all the work of photosynthesis.

Pots And Pans Need Cleaning

30918thumbThis is getting to be cliché. “While they are dormant through winter”, plants tolerate all sorts of abuse that would offend them at any other time of year. It applies to planting bulbs and bare root plants. It also works for pruning deciduous fruit trees and roses. It is a predictable seasonal pattern. Most winter gardening is contingent on dormancy. Processing potted plants is no exception.

Plants that have gotten too big for their pots should be replanted into larger pots. Any circling roots should be severed, just as if the plants were going into the ground. Unlike planting into the ground, potted plants require artificial media, known simply as ‘potting soil’. If larger pots are not an option, overgrown plants must at least be pruned to stay proportionate to their confined roots.

A plant that has been in a pot long enough for the media to decompose and settle might benefit from being ‘stuffed’. This involves removing the root mass from the pot, adding just enough media to the pot to support the root mass at the desired level, replacing the root mass on top, and then adding more media around the root mass to fill the pot. Exposed surface roots can be buried too.

Many overgrown succulents (not including cacti) can be replanted lower instead of higher. If settled, more media can be added on top. If all the foliage is clustered on top of bare stems, the stems can be cut and ‘plugged’ as new plants into pots of media, while the old roots and basal stems can be left to generate new stems and foliage. Newly plugged stems will generate roots by spring.

In the processes of potting, stuffing and plugging, while pots are empty, it would be a good time to scrub away mineral deposits from the bases and inner rims of pots. These deposits tend to accumulate just above the surface of the potting media, and where pots sit in water that drains from them. The pans or saucers that contain drainage water also accumulate mineral deposits. While plants are being processed, they can be groomed of deteriorating foliage and other debris.