Ask Mr. Smarty Plants

There are no hard-and-fast rules for timing of transplanting since there are many exceptions to any rule regarding horticulture, although there are some general rules that apply to most plants. In general, the best time to move a potted plant up to a larger pot is when it just becomes pot-bound. The worst time to transplant most plants is when they are flowering or are about to flower. Just after flowering (and fruiting) is complete is usually the best time to transplant. When your plant just begins producing new vegetative growth after a period of dormancy is also usually an ideal time to transplant. It is a good idea in most cases to remove 1/3 to 1/2 of the top growth of most plants when transplanting, especially during warm or dry periods. The great shock of being transplanted causes most plants to be water stressed during the time immediately after transplanting. Excess existing foliage will usually cause the plant to dry out and die. More than likely, this has been the cause of the problem you have experienced when transplanting your plants. Protect newly transplanted plants from direct sun or windy conditions until they are well-acclimated and well-rooted -- usually a few weeks to a few months. Try not to disturb the roots any more than necessary when transplanting. However, it is often a good idea to gently loosen the roots at the bottom of the rootball with your fingers before putting the plant into a larger pot. Be careful not to bury the root ball. You should put no more than about 1/4 inch of soil on top of the existing rootball when you transplant. Try not to cover the crown (base) of the plant with any soil at all. It should be at the same soil level as it was in the old pot. In general, potting soil should contain lots of organic matter, but should drain well, too. Heavy field soil becomes too compacted in a pot for growing most plants. Water well upon transplanting, but do not overdo the watering. For awhile, the new soil in the larger pots is likely to stay wetter than the soil of the old rootball. As new roots penetrate the new soil you will see less difference in soil wetness than at first. It is best not to feed newly transplanted plants until they have a chance to establish new roots and begin actively growing. Then feed sparingly for awhile until the plants are well established.