Q. A friend gave me four fig tree saplings in a five-gallon pot. They produced fruit last summer. How should I plant them, and how do I take care of them? What type of soil do they prefer and how much should I fertilize them? Are they winter hardy in our climate? If not, can I grow them as houseplants?

A. Edible figs (Ficus carica L.) are not reliably winter hardy in our USDA zones 5-6; they are considered hardy in USDA zones 8-10, where winter temperatures rarely go below 15 degrees. At this point, wait until spring to plant them outside or transplant them into separate containers.

If planted outside in our climate, fig tree roots usually survive the winter, but the top growth is killed back to the ground. If the variety produces fruit on new growth, you may still get a harvest late in the growing season. However, our growing season is not always long enough and an early frost can kill the tender crop before it is ready to harvest. If your fig trees are one of the varieties that produces its crop on last season's growth, you may never get to enjoy another crop. The varieties that perform best in Northern climates are 'Celeste,' 'Brunswick,' 'Marseilles,' 'Osborne Prolific' and 'English Brown Turkey.' They ripen a little earlier than other varieties, and bear fruit on the current season's growth.

If you choose to plant any of your trees outdoors, select a sheltered area that receives 8 to 10 hours of sun a day. A southern exposure near your house or a wall would be ideal. Figs actually do best in a somewhat poor soil that has excellent drainage; avoid low spots where water tends to collect. That moisture in the winter will kill a fig tree quicker than anything else.

Even those varieties of figs considered hardier and better suited to our climate need special attention to survive winter and produce fruit the following season. Although you may read about gardeners bundling up their fig trees in burlap, polyfoam insulation or other protective coverings, the most reliable way to protect them is to uproot one side of the tree, lay it down and bury it under an insulating layer of mulch and soil.

Dig a 2- to 3-foot deep trench on one side of the tree, running outward from the tree, and as long as needed to completely bury the crown. Start the trench about 1 1/2 feet away from the trunk of the tree. Then on the opposite side of the tree, dig down through the roots and uproot the tree until you can lay it down into the trench. You can use outdoor grade plywood to cover the tree, topped with 12 to 18 inches of straw or shredded leaves, then topped with the soil you dug out to create the trench. Be sure that any exposed roots are covered thoroughly with 2 or 3 feet of soil.

If that sounds like too much work, consider growing your figs in containers year-round. That way you can move them into a protected area such as an integral garage for the winter. This is really the most foolproof way to make sure you get a harvest every season. It would be wise to give each tree its own five-gallon container (at least). As they grow, you will need to move them up into larger containers. Be sure the containers you choose have drainage holes in the bottom.

Use a good quality potting mix that drains well, yet holds adequate moisture. Never use soil from your yard or garden. Our clay soils compact too tightly and hold too much moisture. Also, you can introduce soilborne disease problems by using soil from your yard. It also wise to avoid the very light, soilless, seed-starting mixes. They dry out very quickly and may not hold enough moisture to get your trees through a hot summer day. A potting mix that contains sterilized soil along with peat, perlite and vermiculite is ideal. You could also work in one part sifted compost to every three parts of potting mix to make a heavier growing medium.

Work a coated-release fertilizer such as Osmocote into the potting mix according to label directions. Especially in containers, more fertilizer is never better. Too much can burn tender roots and kill plants outright.

The roots of the four trees have most likely grown together in one container. Pull out the rootball and try to gently separate the individual trees. You will probably have to break some of the roots, but try to make sure that each tree has an adequate root system. Plant the trees in their new containers at the same depth as they were growing in the single container. Try to spread the roots out around the container as evenly as possible.

Move them outdoors into a sunny location once we are past danger of severe frost in the spring. An area that receives sun for 8 to 10 hours is ideal. It is helpful if you can shade the containers to keep the roots from getting too hot, while allowing the fig trees to have full sun.

During the growing season, do not allow the trees to dry out. Check them daily, and water as often as necessary to keep the soil evenly moist, but never sopping wet. When you water, make sure you wet the soil thoroughly until it runs out the drainage holes. During hot summer weather, you will probably need to water them thoroughly every day.

During the growing season, you can use a water-soluble fertilizer such as fish emulsion, Miracle-Gro or Peters 20-20-20 to supplement the fertilizer in the potting mix. Quit fertilizing by mid-July so that the trees harden off for winter. As fall approaches, allow your figs to be exposed to a few light frosts to cause leaf drop and encourage them to go dormant for the winter. Then move them into a garage, cool basement or other space where temperatures do not go below freezing, but where it stays fairly cool (under 40 degrees) so the trees stay dormant. You will not need to water very often while they are dormant, but check the soil periodically. You do not want the roots to completely dry out, either.