Here's a guide to fall feeding -- enjoy!
* Fall is the time of year to switch from the high nitrogen orchid fertilizers to the bloom formula for cymbidiums.
* Bloom fertilizers (0-10-10) can also be applied starting now to the following cool season and spring blooming plants like azaleas, camellias, rhododendrons, and hydrangeas. If you are trying to keep blue blossoms blue you should also apply Aluminum Sulfate to the soil around the drip line, in spring it will be too late.
* Phosphorus (the second element listed on the fertilizer package) not only stimulates root growth, blooming and seed production but also promotes winter-hardiness.
* Potassium (the third element listed on the fertilizer package) imparts vigor and disease resistance, so the bloom fertilizers basically strengthen a plant’s immune system going into winter.
* When the soil temperatures drop some plants can’t take up the iron they need and their leaves can turn yellow. Those plants are good candidates for foliar feeding with Maxsea to keep them green.
* Rose Care--September 15 is absolutely the last time to apply a liquid nitrogen fertilizer to roses. Fertilizing any later may lead to excessive new growth that will become badly diseased when the rains start up in October. Since organic fertilizers typically take 4-6 weeks to break down and be available to the rose bush, organic fertilizers should be avoided until next February. In the Bay Area the ‘Indian Summer’ of September and October are often the warmest months of the year so regular watering should still continue until the rains start in earnest.
* Old petals and yellow leaves that drop should be picked off /raked up. The yellowing of the leaves is a normal, natural process at this time of year. The old leaves must go straight into the garbage (or green compost bin in SF) and NOT in the compost pile in the back yard. The back yard pile will not produce high enough temperatures to destroy disease spores. Rose growers should also stop dead-heading and pruning their roses. A rose bush’s ‘goal’ is to produce seeds (rose hips). Once the hips start to swell, germination has taken place and seeds are starting to develop. Roses will be stronger and healthier if they rest all winter. In fact some of us even cut off all the rose leaves in December. Cutting the leaves off instead of ripping them off will prevent damaging the bark where the new dormant bud eyes are located. Removing the leaves will also make it easier to apply dormant spray, which will help control over-wintering disease spores and insect eggs. Look for our Rose Pruning seminars in January and February.
