The Campbell Reporter
Gardening
Just Leaves: Staghorn ferns are tropical epiphytes that normally grow on trees, obtaining nourishment from ambient moisture and decaying leaf litter. They grow best in filtered or indirect light.
The weather's turning cold, so cool it with the watering
By Tony Tomeo
Lawns and gardens need the most water during the warmest summer weather, less during cool weather and none at all when winter rain provides more water than they can use. Although it is still too early to stop watering completely, most resilient woody plants that are normally watered, particularly those that are already dormant, would not complain about getting substantially less water, or even none at all. Only lawns and shallow rooted plants actually need regular watering until the rain starts, and even they do not need very much.
Plants simply are not as active during cool weather as they were in summer. Many will eventually go dormant through winter. For the same reason that bears do not eat when they hibernate, plants do not need much water when they are more or less dormant.
Even plants that remain relatively active and well foliated through winter require less moisture because they lose less through their foliage. Evaporation from foliage, or "evapotranspiration," is as natural to plants as photosynthesis and respiration. Active plants continue these processes during cool weather, but less moisture can evaporate into cool air, particularly if it is also humid. This is why laundry dries so slowly on the line in winter. Soil stays damper longer also.
Of course, deciduous plants that lose their leaves need the least water. Not only are they completely dormant, but they lack foliage for moisture to evaporate from. They need soil to retain only enough moisture to prevent their roots from desiccating. Even seemingly dry soil contains enough moisture for that.
There will never be an exact formula for determining how much water a garden needs at any particular time or for any particular weather conditions. It is something that needs to be determined by observation. Soil that is always muddy, puddling or mossy is obviously getting too much water. Depending upon the plants, soil should be somewhat dry at the surface before it gets watered. A dry surface does not necessarily mean the soil is dry below, but is a good indication that it is draining somewhat.
Trees and plants with coarse, woody or deep root systems prefer infrequent watering. Lawns, annuals and plants with finely textured and shallow roots prefer moderate, but frequent irrigation. Trees in lawns have no choice but to take what the lawn needs through summer, but will respond to excessive watering by producing shallow, buttressed roots. Root rot also becomes a serious problem while the weather is warm.
Once the rain starts, everything in the garden will be getting much more water than needed. Fortunately, tree roots that would otherwise come to the surface do not grow much until the weather gets warmer after the rain stops. The fungal pathogens that cause root rot during summer are likewise not nearly as active during cool rainy weather.
Plant of the Week:
staghorn fern
There are a few ways for forest and jungle plants to compete for sunlight. Self-reliant tall trees grow high above their competition. Opportunistic vines let the trees do the work of getting to the top of the forest, and then climb the trees to get to the top. Passive understory plants produce large, dark green leaves to utilize the sunlight that gets through the higher canopy. Epiphytes are the most resourceful, growing where other plants cannot. Some grow in fissures high on cliffs. Most grow in trees, where leaf litter collects in branch unions.
Staghorn ferns, Platycerium bifurcatum, can grow on cliffs and trees, even without fissures or branch unions. In the garden, they are quite happy on slabs of bark or coarse wood. They simply attach themselves wherever they like and start collecting their own leaf litter. Their fine roots grip flat surfaces and are covered by flat, pale green fronds that fade to papery brown. The upper margins of these flat fronds curl slightly outward to collect leaf litter that might fall from above. Narrow, forked "staghorn" fronds reach outward as far as 2 1/2 feet. Large plants are easy to divide. Because staghorn ferns grow on vertical surfaces, they need to be hosed to get watered, but only when they begin to get dry.
Listen to Tony Tomeo's 'New Image Garden Report' Friday mornings at 8:10 a.m. on KSCO-1080 AM (or online at www.ksco.com). He can be reached at www.ttomeo@newimagelandscape.com or 408.358.2574.
