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.

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.

‘Silver Falls’ Dichondra

80124No one seems to know what ever happened to old fashioned dichondra lawns. Everyone seemed to like them, especially those of us who dislike turf grasses. Somehow, they became passe and very rare. The formerly common dichondra that such lawns were made of is now merely a resilient weed in turf lawns. But wait! We have not heard the last of this resilient and appealing perennial.

Silver Falls dichondra, Dichondra argentea ‘Silver Falls’, has the same tiny rounded leaves, dense growth and fine texture as old fashioned dichondra lawns, but instead of rich deep green, it is strikingly silvery gray. It does not tolerate traffic well enough to work as lawn, but is a distinctive small scale groundcover, and cascades exquisitely from urns of mixed perennials or hanging pots.

The trailing growth spreads indefinitely over the surface of the soil, but is not very fast about it. As ground cover, individual plants should therefore be planted only two or three feet apart. They get two to four inches deep. Hanging growth (that can not root into the soil) can cascade more than three feet downward. Silver Falls dichondra prefers regular watering and full sun or a bit of shade.

Sweet Pea Shrub

70111It may not always bloom profusely, but sweet pea shrub, Polygala fruticosa, blooms sporadically through most of the year. Even when not much color is evident from a distance, a few flowers can likely be found on closer inspection. For some reason, bloom seems to be quite colorful now. Bloom phases should be more profuse in spring and summer. The pea flowers are soft purplish pink.

Mature plants might only get to two or three feet tall and wide, but have the potential to get larger. They are usually a bit wider than tall, with a nice rounded compact form. The evergreen foliage is slightly grayish light green. Sweet pea shrub prefers full sun exposure, but can get roasted in hot spots. A bit of shade should not be a problem. Once established, it does not need too much water.