Potted Plants Need Work Too

Most potted plants would prefer to be in the ground, . . . if possible.

Potted plants can be a problem any time of the year. Some want more water than get. Most get too much water or do not drain adequately. Large plants get constricted roots if pots are too small. The roots of some plants get cooked in exposed pots that collect too much heat from sunlight. Besides, too many pots just seem to be in the way in otherwise useful spaces on decks, patios and anywhere else trendsetting landscape designers want to put them.

Now that the weather is getting cool and rainy, potted plants are not as active as they were during warm weather. Many are dormant. Although few demand the attention that they got during warmer weather, plants still need to be tended to appropriately through autumn and winter.

Cool season annuals, which are also known as ‘winter’ annuals, should get groomed as long as they are performing in the garden, just like warm season annuals get groomed through summer. Deteriorating flowers should be plucked from pansy, viola, primrose, Iceland poppy, calendula, dianthus, stock, chrysanthemum and cyclamen because they can mildew and spread mildew to developing flowers and foliage. Unplucked cyclamen and calendula can develop seed which diverts resources from bloom.

Pots that are out in exposed areas will not need to be watered while they get enough water from rain. The problem is that many that do not drain adequately can get too much water from rain and stay saturated. Dormant and defoliated plants do not need much moisture at all. Even evergreen plants do not need as much as they do while active during warm weather, because cool and humid weather inhibits evapotranspiration (evaporation from foliar surfaces).

Potted plants under eaves also need less water while the weather is cool and humid, but need to be watered nonetheless because they are sheltered from rain. Plants in hanging pots typically drain and dry more efficiently, so probably want a bit more water. Even a few sheltered small plants in the ground may occasionally want to be watered during rainy weather if they do not extend enough roots where they can get moisture from rain beyond the sheltered area. Sheltered plants are actually the most likely to be neglected because watering does not seem so important when it is raining.

Not All Plants Like Fads.

Ornate pots and planters can be as decorative as the plants within them, and provide extra accommodation for more plants.

Like so many fads too often are, container gardening is overrated, and is actually contrary to the currently most faddish of fads; sustainability. Plants in containers need more regular watering than those that can disperse their roots more extensively into the ground. Those that are so indulged also want fertilizer to be applied more regularly, but are more likely to be damaged if fertilized too generously. Because confinement is stressful, plants in containers are innately more susceptible to disease and pests. Some plants need more pruning for confinement.

Then there are the problems with the containers. If exposed to sunlight, thin plastic containers get warm enough to cook roots within. Pots that do not drain adequately or that sit in their own drainage basins can stay saturated enough to kill roots. Water in drainage basins allows mosquitoes to proliferate. Seepage from large pots can rot decks and stain pavement. Self watering containers work nicely for houseplants (if used properly!), but lack drainage, so can not be used out where they are exposed to rain.

The advantages to container gardening are actually quite limited. Containers are obviously needed for houseplants, and where exposed soil is not available, like on balconies. They are also convenient for plants that want better soil than they can get in the garden, especially if the rest of the garden is responsibly landscaped with sustainably undemanding plants that do not require soil amendment or regular watering. Frost sensitive plants can be moved easily to sheltered locations if contained. Flashy plants like orchids and tuberous begonias that get displayed prominently while blooming can be concealed while not so impressive.

Of course there are many pendulous plants like Boston fern, spider plant, string or pearls and burro’s tail that really are at their best in hanging pots. It is also hard to deny that there are all sorts of artsy containers, like colorfully glazed pots and sculptural concrete urns, which are appealing enough to justify growing plants in them, even if just to show off the fun containers. Bonsai requires containers, but that is another big topic!

Roots Prefer To Roam Freely

Some yuccas are unhappy in pots.

Roots are innately mysterious. They consume much of the resources that plants require. They stabilize the stems above them. Few plants can survive without them. Yet, roots are very secretive about their work. Almost all are invisibly subterranean. Consequently, they get minimal consideration. A lack of consideration is a root cause of many root problems. 

Every plant species has distinct environmental preferences. Some plants require full sun exposure. Others tolerate or prefer partial shade. Some are more discerning than others. Similarly, plants that naturally disperse their roots extensively dislike confinement of their root systems. Small plants and some riparian plants are more adaptable to confinement.

Annual bedding plants and many small perennials perform well within pots, planters and small spaces because they do not need to disperse their roots extensively. Some woody plants with fibrous root systems, such as azalea, boxwood and andromeda, can adapt to confinement also. Occasional pruning can keep them proportionate to their root volumes. 

Most of the popular succulents perform remarkably well in confinement. Some types that disperse their roots extensively if necessary will adapt to confinement by dispersing their roots only as far as they must. If they get all they need within a pot, they need not go any farther. However, succulents that are endemic to dry desert regions are not as adaptable. 

Desert plants can survive warm and dry summers because they disperse their roots very extensively. They can not do so within the confinement of pots and planters. This should not be a problem that systematic irrigation can not compensate for. Unfortunately though, these same plants are too susceptible to rot if their roots are damp during warm weather.

So, some plants that are the most resilient in the ground are the least resilient in pots. Of course, this is not an absolute rule. Yuccas from tropical and temperate climates perform well either in the ground or in pots. Those from desert climates are likely to rot in pots. In general, drought tolerance and container gardening are two fads that are not compatible. 

Planters Are Overrated But Functional

Some plants should always be confined.

Container gardening is overrated. The endemic soil here is not so bad that nothing will grow in it. What is now suburban gardens was formerly famously productive farmland! Soil amendments make the soil more comfortable to plants with more discriminating taste. Plants that are too discriminating are probably not worth accommodating. With few exceptions, planters are unnecessary.

Plants naturally want to disperse their roots into the soil. Drought tolerant plants disperse their roots even more extensively. That is how they find enough moisture to be drought tolerant. If deprived of such root dispersion, they are always reliant on watering. Plants prefer the insulation of soil too. Many types of planters can get uncomfortably cool in winter, and uncomfortably warm in summer.

Besides, planters clutter landscapes, and occupy space on hardscapes. Decks rot. Patios stain.

The main advantage of planters is their portability. Plants that are sensitive to frost can move to shelter before the weather gets too cool. Plants that are spectacular only while blooming can move for more prominent display during bloom. For those who have not settled into a permanent home, plants in planters are able to relocate. Planters on patios or decks can move about like furniture.

Houseplants obviously grow in planters because not many houses contain enough soil for them to live in. Houseplants can move about just like planters in the garden. That is helpful for those that need a better exposure for winter than they enjoy for the summer. Some might like to go into the garden during mild weather, or for a rinse in light rain. Cascading plants can hang from the ceiling.

Planters can effectively confine invasive plants as well. Montbretia is so invasive that some people will not grow it without containment. (Deadheading to prevent seed dispersion is important too.) Horseradish often grows in tubs for confinement, as well as to facilitate harvest. It is easier to dump the potting media from a planter, and separate the roots out, than to dig roots from the ground.

Potted Plants Need Work Too

Potted plants do not have much soil volume to work with.

Potted plants can be a problem any time of the year. Some want more water than get. Most get too much water or do not drain adequately. Large plants get constricted roots if pots are too small. The roots of some plants get cooked in exposed pots that collect too much heat from sunlight. Besides, too many pots just seem to be in the way in otherwise useful spaces on decks, patios and anywhere else trendsetting landscape designers want to put them.

Now that the weather is getting cool and rainy, potted plants are not as active as they were during warm weather. Many are dormant. Although few demand the attention that they got during warmer weather, plants still need to be tended to appropriately through autumn and winter.

Cool season annuals, which are also known as ‘winter’ annuals, should get groomed as long as they are performing in the garden, just like warm season annuals get groomed through summer. Deteriorating flowers should be plucked from pansy, viola, primrose, Iceland poppy, calendula, dianthus, stock, chrysanthemum and cyclamen because they can mildew and spread mildew to developing flowers and foliage. Unplucked cyclamen and calendula can develop seed which diverts resources from bloom.

Pots that are out in exposed areas will not need to be watered while they get enough water from rain. The problem is that many that do not drain adequately can get too much water from rain and stay saturated. Dormant and defoliated plants do not need much moisture at all. Even evergreen plants do not need as much as they do while active during warm weather, because cool and humid weather inhibits evapotranspiration (evaporation from foliar surfaces).

Potted plants under eaves also need less water while the weather is cool and humid, but need to be watered nonetheless because they are sheltered from rain. Plants in hanging pots typically drain and dry more efficiently, so probably want a bit more water. Even a few sheltered small plants in the ground may occasionally want to be watered during rainy weather if they do not extend enough roots where they can get moisture from rain beyond the sheltered area. Sheltered plants are actually the most likely to be neglected because watering does not seem so important when it is raining.

Nursery Cans Are Only Temporary

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Nursery cans are not permanent pots.

Garden enthusiasts would understand the temporary nature of nursery cans better if they knew more about how plants grow in nurseries. Few plants actually grow in the retail nurseries that market them. They grow in production nurseries, where efficiency is a priority. Nursery cans, which retailers and consumers refer to as ‘pots’, are the most efficient means with which to contain the crops.

Most nursery cans are thin black vinyl. While plants are small, crowded ‘can to can’ arrangement shades the black vinyl so that it does not get too hot from sunlight exposure. Those on the western and southern edges of a crop might get shade from a temporary row of empty cans or a plank leaned against them. As plants mature and need more space, their growing foliage shades the vinyl.

As plants become marketable, they go from production nurseries to retail and wholesale nurseries. From there, they go to new landscapes and home gardens. Only then do they finally escape the nursery cans that they grew up in, to disperse their roots into real soil. The nursery cans have finished their job. Plants can not live in them forever, even if they continue to live in other types of pots.

Nursery cans are efficient, but not necessarily comfortable. By the time they are marketable, the plants that they contain are generally about as big as they can get within their cans. If they get any bigger, their roots will be crowded. If too exposed to sunshine, the black vinyl gets hot enough to cook the roots within. Plants prefer to be in the ground, or at least pots that are more comfortable.

Potted plants that will grow bigger should live in pots, planters or other containers that are bigger than the nursery cans that they grew in. Some will want even larger containers as they grow more later. Annuals and plants that will not grow much bigger are not so critical. However, all potted plants that will not shade their own pots appreciate containers that are better insulated than thin vinyl.

Clay pots, wooden planters and even concrete urns are as practical as they are appealing.

Pots Make More Out Of Less

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Half barrels are a bit elevated, and seem to show off their flowers better.

With conservation of water being so important right now, annuals are not a priority. Many of us are trying to use as little water as possible, and only to keep the more significant trees, shrubbery and perennials alive until winter. Lawn and annuals are usually the first to succumb, mainly because they use more water than anything else.

They are also somewhat expendable. Lawn is certainly expensive, but realistically, can be replaced as soon as water becomes available. Hopefully, new lawns will be more conservative with water, like they should have been since the last “drought” (and the one before that). Annuals are planted annually (duh), so they get replaced anyway.

Annuals as bedding plants over large areas were already somewhat passé before the last few dry winters. Even the more indulgent landscapes used annuals merely as relatively modest borders around or in front of more substantial, but less consumptive, perennials and shrubbery. Pots and planters are already more appropriate.

Some of the trendiest big pots are so ornate that they do not need flowers to provide more color. Besides, with a few striking perennials for colorful foliage or form, there is not much space left for annuals. What matters with annuals is that fewer in a pot can be flashier than more in the ground. Fewer annuals mean less water is required.

Elevated planters may not be as ornate, but display flashy annuals just as effectively. Petunia, million bells, lobelia and alyssum can cascade over the edges, to be colorful both on top and on the sides. Marigold, zinnia, celosia and any interesting foliar or sculptural perennials get a bit more height. It all helps to get a bit more out of less.

Pots and planters are not necessarily less work. They just need less water than larger beds, because they are smaller. Relative to their area, they actually need more water, and must be watered very regularly to sustain the confined roots within. Hanging pots need the most water. All confined plants benefit from fertilizer.

Horridculture – Slim Waists

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If I put a spider plant in the pot on the right, I may never get it out.

Clay pots have been around for a very long time. It is impossible to know for how long exactly. It is logical to say that they have been around long enough to evolve into the perfect shape for their function. Although the dimensions and proportions are variable, the basic design characteristics of the simplest and best engineered clay pots can not be improved on.

Clay pots are circular from above and below for a few reasons. Such a shape is easily formed on a potters’ wheel. It is more structurally sound than a form with flat sides and more corners. The space within is evenly distributed around the vertical center, without more remote corners. Although roots will circle within, there are not so many corners for them to congregate in.

Drainage holes are at the bottoms because that is where water drains to.

Thick rims around the top edges of common clay pots enhance durability where it is most necessary, and also prevent pots of the same size from becoming wedged into each other when stacked. The weight of stacked pots rests firmly and vertically on such rims, rather than being diverted laterally to break wedged pots to pieces.

It would not be possible to stack clay pots if they were not tapered to be wider on top. Of course, they are tapered for a few reasons, just like they are circular and outfitted with rims for a few reasons. Tapered form fits the natural dispersion of the roots of most plants better. More importantly, tapered form facilitates the removal of firm root systems with minimal disruption.

So, after perhaps thousands of years of evolution to achieve the perfect form, who thought it was a good idea to taper pots inward at the top? The lack of a rim is not so important if pots are not so numerous that efficient stacking is a concern. Such pots can not be staked anyway. They do not get reused as much as common clay pots either, so do not need to be so durable.

However, that upper inward taper is a serious problem for plants that mature and develop firm root systems within. Such mature plants can only be removed from such pots only by tearing their root systems apart, or by breaking the pots apart. Such form is only practical for big pots that contain multiple small plants that, individually, do not get big enough to fill the pots.

For example, big urns of bedding plants or mixed perennials function more as planters than as pots. Bedding plants get removed and replaced seasonally, and even if the don’t, they can not get big enough to develop a solid root system that is wider than the inwardly tapered top of a big urn. Likewise, most perennials get removed from such big pots before they get stuck within.

Palms, agaves, yuccas and other more substantial perennials must not be allowed to live within an inwardly tapered urn long enough to develop a firm root system that can not be removed.

Horridculture – Going To Pot

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Would these hanging potted plants even be noticeable if they were not circled?

Container gardening is overrated. Perhaps not so much now as it had been while it was more of a fad a decade or so ago, but it is still overrated nonetheless. Most plants are happier in the ground than they are in confinement. They want to disperse their roots freely to where the goodies are, and not contend with the unnatural temperature fluctuations of contained medium.

There are only a few exceptions for which containment of potted plants is an advantage. Houseplants are the most obvious exceptions. Also, plants that are sensitive to frost can be relocated to sheltered situations for winter if contained. Potted orchids and other flashy bloomers can be prominently displayed while blooming, and then returned to utilitarian locations as they finish.

The justification for the hanging potted plants in the picture above escapes me. Does anyone besides me even notice that they are there? They are hung too high for anyone on the sidewalk to appreciate them, or actually see the flowers that are visible from above. Those on the opposite sidewalk can see them, but only at a great distance across all those lanes of El Camino Real.

Those in cars on the road see less of them than pedestrians. Even those who happen to look up while riding past in convertibles with the tops down will see only the undersides, and only at significant speed. These potted plants would be in the way of the sidewalks if they were lowered to be more visible. No matter where they are, they are not proportionate to the broad road.

Maintenance of the flowers in these many hanging pots was quite a bit of work. The annual flowers needed to be replaced a few times a year, or more if ruined by the weather. Without automated irrigation, someone needed to manually water them, which left puddles on the sidewalks that were more noticeable than the highly hung pots above.

As if all these hanging pots were not already tacky enough, the flowers within were eventually replaced with . . . fake flowers, as seen in the picture below.

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Just when it could not get any tackier; they are fake!

Do Not Forget Potted Plants

30918thumbAside from all the seasonal raking and dormant pruning, there is not as much to do in the garden as there was earlier in the year. Lawns do not need much mowing. Hedges do not need much shearing. Untimely mowing and shearing can actually damage lawns and hedges. Watering, which was so important while the weather was warm, is now rare in the cool weather between rain.

Watering is now so infrequent that the few plants that still need it sometimes do without. Plants that are merely sheltered by eaves probably do not mind so much because their roots are dispersed beyond the eaves. However, potted plants that are sheltered by eaves do not have that option. It may take a while in the cool and damp air, but they can slowly get uncomfortably dry.

Watering sheltered potted plants is too easy to forget about while everything that is not sheltered is getting soaked by rain. It is even more easy to forget because it is so infrequent. Things just do not dry out like they do in summer. Also, plants are less active, and many are dormant and defoliated, so really do not lose much moisture to evapotranspiration (evaporation from foliar surfaces.)

In fact, overzealous watering can be just as detrimental as neglect. Soil saturation may not be as immediately dangerous as it would be during warmer weather, but eventually kills roots. Even with adequate drainage, soil moisture can linger if plants do not consume it. Determining how much water is needed for sheltered potted plants may not be as simple as it should be.

Larger plants in smaller pots want more water than smaller plants in larger pots. Those that are exposed to wind will get dry faster than those that are protected. Hanging pots dry out the fastest. Ironically, drought tolerant plants that need the least water in the ground often want the most in pots. They are the most reliant on extensive root dispersion, which is not possible in confinement.

Some potted (frost tolerant) plants might get slightly relocated out into the weather so that they get the rain that keeps the rest of the garden well watered through winter.