Lemons are among the most cold sensitive of all citrus fruit. Because of cold sensitivity, lemon trees should be limited to the south or southeast side of the house and as near to it as the mature tree size will permit. While overhanging shade trees will provide some cold protection, lemons require full sunlight for optimum growth and production.
For the most part, lemon trees will be purchased from a nursery rather than grown at home. Generally, the trees will be container grown in a soil-less medium which makes the trees rather difficult to establish without special care. At planting, use a gentle stream of water from the garden hose to wash an inch or so of the medium from all around the root ball, thereby exposing the peripheral roots. Thus, the outer roots are placed in contact with the soil of the planting site and growth commences almost immediately.
Under no circumstances should soil around the proposed planting site be removed to form a shallow basin for watering to do so almost guarantees that the young lemon tree will contract foot rot and die before its fifth year. The soil in the planting site should be at least as high as the surrounding yard, if not higher. In addition, the tree should be set at the same depth or slightly higher than it was in the nursery container to assure that the bud union will remain well above the soil.
Mixing topsoil, compost, peat or other materials with the back fill soil is neither necessary nor desirable in good soils. Set the tree in the hole, back fill about halfway, then water sufficiently to settle the back fill around the lower roots. Finish back filling the hole and then cover the root ball with about in inch of soil to seal the growing medium from direct contact with the air and thereby
prevent rapid drying of the root ball.
To facilitate watering, bring soil from the garden or elsewhere to construct a watering ring atop the ground around the newly planted tree. The ring should be about two feet across and several inches high and thick. To water, just fill the water ring immediately after planting. After the water soaks in, it may be necessary to add a little soil to any holes formed as the soil settled around the roots.
The watering interval should be every few days for the first couple of weeks, then gradually increase the interval to 7 to 10 days over the next couple of months. The watering ring with gradually melt into the surrounding soil, at which time the young lemon tree can be considered to be established.
All weeds and lawn grass should be completely eliminated inside the watering ring, as the developing lemon tree cannot compete well. A systemic, contact herbicide will work very well, so long as it is not allowed to contact the young tree leaves or green bark.
The best way to protect the young trunk from herbicide damage and, at the same time, to prevent sprouts along the trunk is to crimp an 8inch by 18inch piece of heavy duty aluminum foil around the trunk from the ground to the scaffold limbs. Fold the foil lengthwise, bring the long edges past the trunk on both sides, crimp the two edges together and lightly squeeze the foil around the trunk.
Mulching is not recommended for citrus because it increases the possibility of the tree contracting foot rot, for which there is no cure. If you insist on mulching, keep the mulch at least a foot away from the trunk.
Fertilizer should be withheld until after growth commences. During the first year, a single cupful of ammonium sulfate (2100) split into three or four applications is adequate. Use 2 cups in the second year and three in the third. Just scatter the fertilizer on the ground around the tree and water thoroughly.
Cold protection measures for lemon trees will be required sooner or later. Soil banks are very effective for young trees? the soil should be put up about Thanksgiving and left in place through February. Exercise care when taking down the soil bank, as the bark underneath will be extremely tender.
Blankets, tarps or similar covers are also very effective and have the advantage of being quickly draped over the young tree. The corners should be stretched outward and tied down. More elaborate protection can be provided by erecting a frame structure of wood or PVC pipe over the plant to facilitate the use of plastic or large tarps during particularly severe cold weather. Supplemental heat
can also be provided under the covers? incandescent heat lamps and Coleman lanterns are useful.
MATURE TREE CARE
Watering should be slow and thorough? probably every couple of weeks would suffice in any but the very sandy soils. Nutrition should continue at about 1 cup of ammonium sulfate per year of tree age annually in split applications in February, May and September, i.e. a 6yearold tree should receive about 6 cups of 21-0-0 for the year. Adjust the rate for other fertilizers based upon the relative
Lawngrass should be kept back about a foot from the canopy of the tree. Other than cold damage, no pruning should be necessary, as the lemon tree will develop its natural shape without pruning. While mulching is not recommended for citrus trees, if you must mulch, keep the mulch at least one foot away from the tree trunk.
Meyer' lemons bear mainly in fall to winter. At full maturity, the fruit will turn yellow on the tree. However, they may be sufficiently juicy to use
before they change color. While true lemons must be cured for a couple of days in order to sustain
commercial marketing, curing should not be necessary for those that will be used directly from the tree.
There are very few lemon tree problems that are life threatening and the home gardener cannot do anything about those anyway. Many of the rest of the insects and diseases that afflict lemon trees can generally be ignored in the home garden, as blemishes to the peel affect only the appearance, and, in some cases, size of the fruit.