Figs need regular watering to get established; however, over-watering is more of a problem than under-watering. If you are under-watering your tree, the leaves will wilt a bit to let you know to give them some attention. Once a fig tree is established in the ground, it seldom needs watering.
A fig tree’s roots need to be well-oxygenated, which is why a nice loamy / sandy soil with good compost is preferable. Clay is the worst soil type; worse yet is clay that’s been amended with sand in an attempt to “fix it.” If you have clay-type soil, your best bet is to remove it completely and replace it with compost, garden soil, etc. The soil’s pH is not the most important thing, but fig trees do best in slightly sweet soil (pH > 7). Some growers add gardening lime, but this usually is not necessary.
Fig trees can survive with very little nutrients and are a lot more “forgiving” than most plants. Slow-release fertilizer, compost tea, etc. are good improvements, but Miracle Grow is not advised from my experience. Any organic fertilizing techniques are most certainly advised, and I have had excellent results to back it up. Mulching is quite helpful for water retention and can also add small amounts of nutrients if the contents are semi-decomposed.
Good news – fig trees invite very few pests thanks to an enzyme called ficin – a protease that dissolves/breaks down proteins – that’s found in the stems, branches and leaves. Typically, if an insect, small mammal or even deer try to snack on the plant itself, it will be the last time that they visit as they will experience inflammation of the lips, throat and mucous membranes. Birds, on the other hand, can steal ripe fruits (dark ones) by clipping them, which can in turn invite other pests like bees, hornets or ants that are attracted to the open or damaged fruit. Netting and metallic tape is helpful in deterring birds from dark fig varieties.
This ought to be #1 on the list due to its importance. If there is one thing that can determine success or failure in cultivating figs, it is their daily exposure to sunlight. Many times when folks are not getting fruit from their fig trees, it is because the trees are not getting the amount of sunlight that they need. Simply put, more sun = more fruit (and the earlier the fruit will ripen). When choosing a spot for your tree, aim for one that gets 6-8 hours a day; south-facing is best. And if the tree gets too full and bushy, prune it so as much of the tree can get full sunlight.
This is also very important to consider. Although fig trees are subtropical, they can do quite well in cooler environments because they are by nature very adaptable. But you should fight the urge to let them figure it out on their own and lend your fig tree a hand to help it survive.
My first piece of advice is to keep the fig tree in a pot for the first two winters. This means getting a big pot and good soil, watering it as needed and tucking it away during the winter in an unheated garage, shed, or basement. Once the tree has a good, thick trunk, its chances of survival go up substantially. And while most folks may shrivel their noses up at this because it is a pain (and I don’t disagree), the reality is that a living tree is better than a dead one.
Secondly, in addition to planting in a south-facing plot, choosing (or establishing) a home with a microclimate is an excellent help. A “microclimate” can be on the side of a building, brick wall, fence, etc – you want something that protects the tree from the northwest wind and also something that radiates heat. Stone, brick and concrete make for excellent heat sinks that will absorb heat from the sun all day long and release it to the tree and soil throughout the night. The temperature becomes slightly higher than the surrounding air temperature and helps the tree survive during very cold nights. Obviously, partial burial, step-over espalier, wrapping, etc. are other labor-intensive techniques that you can employ to help over winter, but remember that most of the trees I sell have been tested in our area unprotected and have a slight genetic advantage over most fig trees sold at big box stores. Employing some of these techniques with a tough-weather-tested cultivar improves your chances of enjoying sweet, rich figs every summer and fall for a long time.