This section is from the book "The Gardener V2", 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.
Apply fire-heat to all strong-growing trees till the wood is well ripened. Look over trees from which fruit has been recently gathered, and remove all superfluous shoots, so as to let light and air play about all the foliage and wood. Should this month be colder and damper than usual, late Peaches under glass will be benefited by fire-heat: it will cause them to swell better and improve the flavour. Where new borders are to be made and young trees planted, the work should be done so that the trees may be planted just as they begin to shed their leaves. Any young trees that have made strong unfruitful shoots should be lifted and replanted at the same time. Keep the earliest trees cool and well aired.
Trees in late houses on which leaves are hanging should have a whisk twice a-week with a broom to bring off such leaves as are ready to drop. Those that are to be started next month should be pruned and tied, and everything about the house and border prepared for starting. Any trees showing a retrograde tendency should be treated as directed for Vines. Where new borders have to be made and young trees planted, such work should be completed without delay; and any young trees that have grown too strong last season should be carefully lifted and replanted, if this has not been attended to previously. All trees in unheated houses are late, and it will be later than usual before they drop their leaves.
Peach-houses and trees being got in readiness for starting, as directed last month, may now have fire-heat regularly applied to them, if ripe Peaches are wanted by the 1st of May. If the weather be mild, begin with a night temperature of 50°; if cold, be content with a few degrees less. Allow a rise of 8° or 10° by day, when there is any sun, before giving air. Still, let hard forcing be avoided, or the wood-buds will get too much the start of the bloom-buds. Syringe the trees several times daily, and keep the air otherwise moist. See that the border is thoroughly moist before fire-heat is applied. Indeed, Peach borders should never be allowed to become very dry. Prune and tie succession trees. Where young trees are yet to plant, no time should now be lost in planting them. In making new borders, put no animal excrement nor leaf-mould in them, - 1/2 cwt. of bone - meal and 1/2 cwt. of half-inch bones to every 6 cubic yards of soil is all that should be mixed with it. The Peach likes a holding, firm, loamy soil, not over 2 feet deep, with the most thorough drainage.
There are few things more injurious in the early stage of Peach-forcing than anything approaching high night - temperatures. The night - temperature in mild weather should never exceed 50°, and when cold, 45° by means of fire-heat, until the blooms are open. High temperatures produce blooms with debilitated organs, and the fruit does not set properly. It also causes the wood-buds to come away too much in advance of the bloom, which is very undesirable. Trees that have long been accustomed to an early start do not need high temperatures to excite them, and if they did, it should be applied by day. Keep a moist genial atmosphere, and syringe the trees several times daily till the bloom opens. When the bloom is fully expanded, and the pollen developed, keep the house warmer by day - it may run to 60°, except in very cold weather - and the atmosphere buoyant and moving by means of ventilation, but always avoiding draughts of frosty air. "With the much earlier varieties of Peaches and Nectarines now in cultivation it is not necessary to start forcing so early, by a month at least, to produce ripe fruit at a given time. A tree of Hales's Early Peach and one of Lord Napier Nectarine in the early house, will give ripe fruit with a few weeks' less forcing than the old sorts.
There are sorts earlier still, but none that we know of combining so many good qualities as those named. All late Peaches not yet pruned should be attended to at once. In pruning, above everything, avoid leaving such a number of young shoots as will crowd the trees, but leave ample room for tying in the summer shoots for next year's bearing without crowding the foliage : as a rule, the bearing wood should not be closer together than 4 inches. In shortening back young growths on trees now occupying all the space upwards, see that the cut is made at a point where there is certain to be a wood-bud. Cutting, too, a triplet of buds, two bloom-buds and one wood-bud should be the rule. Get the planting of young trees completed as soon as possible. Use a rather heavy fresh loam, with no manure added except about half a bushel of ground bones to every square yard of soil.
 
Continue to: