This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
The same directions as to ripening and thinning the wood that have been given for Peaches are applicable to Figs from which the second crop has all been gathered. Keep the foliage fresh and healthy as long as possible, and to this end use the syringe or engine occasionally on fine afternoons. Where late crops are swelling and ripening off, give waterings of dung-water to trees that are old, and bearing heavily in limited borders; and when the fruit are ripening use a little fire-heat, and give a free circulation of dry warm air, or the Figs will be insipid. Early plants in pots that have well ripened their wood but not yet shed their leaves may be placed in a warm exposure outdoors.
Keep trees from which the fruit are all gathered drier at the root, and, provided the wood is well ripened, keep them cool; but young strong-growing trees should be kept warm till they ripen properly. Remove all growths not required for properly furnishing the trees with fruit-bearing wood. Keep a circulation of dry warm air in houses where fruits are ripening.
If any Figs are yet to ripen on the latest trees bearing their second crop, the atmosphere should be kept rather dry and the temperature at 60° at night. Prune and tie the early trees; and if they are old free-bearing trees, apply a rich top-dressing to the border; and if the root-run be limited, so much the richer should the dressing be. Any young trees that are growing too vigorously should be partially lifted and root-pruned, and have nothing richer than pure loam laid on the border.
Where early Figs are produced from pots, a place should now be got in readiness to start them about the middle of the month. A light pit, with a bed of fermenting leaves, into which the pots can be plunged, with a bottom-heat of 80° and a night temperature of 50° to begin with, is the best place for an early start. Top-dress the pots with horse-droppings and bone-meal. Keep the soil moist, and syringe the trees three or four times daily. All trees not yet pruned and top-dressed should not be left any longer. When the summer's pruning has been judicious, little cutting is needed at this season.
This fruit is gaining ground rapidly in gardens, and deservedly so. It is a very productive and wholesome fruit. When well managed it is astonishing how long one tree continues to bear. We gathered fruit from three trees last summer, from June till November, with a very short intermission, after the first crop was over. We have tried a great many sorts, and have found none with so many good qualities as old Brown Turkey. The great points in successful Fig-culture are, to plant in restricted borders, and mix no manure, except a few bones, with the soil, when the trees are first planted. A 6-feet wide border will keep large trees in splendid bearing order for many years, provided they be well nourished with top-dressing and liquid manure after they have attained to a free - bearing condition; but we never find Brown Turkey in anything but a free - bearing state. We have struck it from eyes in February, run it up 4 feet high, and ripened fruit off the young plants in October. Some say the Fig should never be pruned. This is a questionable rule. Certainly the pruning should be carried out when the trees are making their young wood, and very few growths should be retained in summer that need to be cut out in winter.
But to allow trees to become a thicket of wood is quite another and erroneous practice. Every shoot and leaf should have as much space as will let light and air play freely about them, and then next to no winter pruning is called for. Trees started last month should have 5° more heat when they have fairly commenced to grow. The night-temperature, when very mild, may range to 60°, and 5° more by day. Keep the trees moist at the root, and syringe twice daily with tepid water.
Now is a good time to start a Fig - house, furnished with good strong Brown Turkeys, for ripening their first crop in June and July, and their second in September and October. Start at 55° at night. Keep the air moist, and the trees well syringed, and allow a rise of 10° by day. Advance the heat for early trees in pots a few degrees. See that they are well supplied with tepid dung and guano water alternately. It is scarcely possible to over-water Fig-trees in pots that have not been shifted for a few years. It is a good plan to let them root through and over the top of the pots into a mixture of turfy loam and norse-droppings. Few fruit-bearing plants are more grateful for liberal feeding than free-bearing Figs in pots.
Increase the night temperature of the earliest to 60°, with 10° more by day. Figs like a moist atmosphere, and should be syringed twice daily when the weather is fine. The air should never be otherwise than moist until the crop begins to ripen. Attend carefully to the matter of watering, especially when the trees are in pots, or shallow, well-drained inside borders. To stiffen the young growths and prevent the leaves from being thin and tender, give air early and shut up soon in the afternoon. At one time we followed the orthodox practice of stopping the young growths at the fifth or sixth point for the second crop. Now we do not stop any more than is necessary for furnishing the trees with wood, and find that 10 or 12 leaves produced 10 or 12 fruits, just as well as 5 or 6 leaves produced a like number of Figs. Start later trees for successional crop. The 1st of March is good time for starting trees with the view of getting two crops from them by the end of October.