The Meyer lemon trees (Citrus meyeri) you're likely to buy are the "Improved Meyer" cultivar. The standard, disease-harboring Meyer lemons were replaced with this variety in most areas in the 1970s. Like many other citrus fruits, you need to time harvesting Meyer lemons properly to ensure the fruit tastes its best. Meyer lemon trees grow in the warm climates of U.S. Department of Agriculture plant hardiness zones 8b through 10.
Harvesting and Freezing Weather
Meyer lemons will likely have fruit on the tree all year, which means year-round harvesting. This may pose a problem if freezing weather is expected. It's best to grow Meyer lemons in a frost-free climate, but you can grow them in pots in slightly cooler climates. If sub-freezing temperatures are predicted, move a potted Meyer lemon indoors or harvest all the fruit from an in-ground tree and water it thoroughly to moisten the soil around the roots. Picking the fruit before a freeze will protect both the fruit and the tree from freeze damage. If you pick too many lemons from the tree to use right away, squeeze the juice and freeze it.
Meyer Lemons and Ripeness
The color of a lemon, including a Meyer lemon, is not the only indicator the fruit is ready. Because Meyer lemons taste sweeter than standard lemons, is important to know when to harvest the fruit. Color change is a sign your Meyer lemons may be ready, but you should taste a fruit or two for a sweet-tart flavor. When the Meyer lemons taste best is when you need to pick them. The lemons will not become any sweeter after you remove them from the tree.
If you planted a grafted Meyer lemon tree, you may see fruit after two years, but from seedlings, it will take at least four years until you can pick fruit from the tree. When you have decided the Meyer lemons taste right for picking, clip the fruits off the tree with pruning shears, 1 inch above the fruit. This prevents tearing the thin skin of the Meyer lemon. If you accidentally puncture or rip the skin of any lemons during harvest, use them right away or discard them because any damage to the skin could encourage the fruit to breed bacteria at the tear site. You can also gently pull the fruit off the tree while twisting it to loosen it from the stem. If you choose this option, watch out for broken skin on your lemons.
Future Fruit Production
It's a myth that all the fruit needs to be removed from the tree for a future crop to develop. Fruit from Meyer lemons is borne on new growth, not on the old growth that produced the fruit from earlier in the year. If you cannot use all of the fruit at once, leave some on the tree. It will not reduce the amount of fruit the tree produces later, and the best place to store Meyer lemons, like any other citrus, is on the tree.