The care information provided in this section represents the kind of practical advice is available for all the plants in this web site if you subscribe to the monthly customized newsletter Yardener’s Advisor.
Firethorns rarely require supplemental watering except during the season when they're first planted, in time of drought, or in late fall before the ground freezes for the winter. Older, well-established shrubs need watering only during severe drought. During periods when rainfall is scarce and temperatures are high, water firethorns deeply every 10 days to 2 weeks.
For information on products see the file on Choosing Watering Equipment
If you have “good” soil - You may wish to fertilize newly planted Firethorn in the fall of the year after the year in which it was planted. Otherwise, this shrub needs no supplemental fertilizer when growing in good soil and properly mulched with organic material of some kind.
If you have “lousy” soil - Fertilize firethorns once a year in the fall. Sprinkle some fertilizer with a slow release form of nitrogen on the soil under the shrub out to 1 1/2 feet beyond the tips of the branches (drip line) for the rain to soak in. Consult the package label for the amount to use (usually a handful or two depending on the size of the shrub).
For more information see the file for Fertilizers
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A two to four inch layer of organic mulch spread over the soil at the base of the firethorn shrub offers it many benefits. A layer of chopped leaves, compost, wood chips or a commercial mulch such as shredded bark or bark nuggets discourages weeds, conserves water and protects the roots in the winter. It also looks attractive.
Keep the mulch about 6 inches away from the trunk to avoid decay and rodent damage. Over the winter a slightly thicker mulch insulates the soil from extreme variations of soil temperature which cause it to heave and disturb shrub roots.
For more information see the file on Using Mulch
It is not necessary to prune firethorns, but some homeowners like to shape their shrubs. If you feel the plant is getting out of bounds, prune it in late winter or early spring to avoid encouraging diseases. Because firethorns bloom on spurs of wood 2 or more years old, they should be pruned before buds start to open. Pruning later on retards growth and bloom. To encourage more berries, remove wood that has already borne fruit by thinning to well-spaced shoots just outside the outermost flower clusters.
For more information see files on Pruning Shrubs and Choosing Pruning Tools
Really cold winters will cause some firethorn foliage to turn brown, but the plants usually recover easily. Protect shrubs in locations exposed to winter wind and sun with burlap, evergreen boughs, or other screens. Protect any foliage with a spray of anti-transpirant in the early winter, repeating the spray on the first mild day in February. Never use plastic sheeting because it obstructs air circulation around the shrub. Water firethorn deeply before the ground freezes and spread 4 to 6 inches of winter mulch after the ground has frozen.
See the files on Winter Protection For Plants and Plant Protection Supplies