Dates take about 7 months from the time they first emerge from the spath or casing untill they are fully ripened.They like very hot, dry weather and lots of water on their roots.
In the hababuk stage, dates are hand pollinated. In nature, one-half of the palms would be male, but in agriculture, mostly females are planted since only they bare fruit. One male is planted for 50 females. The pollen flowers are cut from the male tree and the pollen is extracted, then applied by hand to the female blooms to assure a good fruit set.
The medjool variety is thinned in the kimri stage at about 9 to 12 weeks. 60% to 75% of the young fruit is taken off. This causes the remaining fruit to grow extra large.
In later Kimri, the fruit stalk is tyed-down to a frond. This positions the bunch and keeps the strings of fruit from being tangled in the fronds.
In late kimri or early Khalaal, the fruit bunches are bagged. This keeps the ripening dates protected from rain. birds and sun burn. This is done with a paper wrap or nylon mesh bag.
Late in the khalaal stage a few varieties can be harvested and eaten in their hard yellow or red state, but most kinds are totally astringent, like an unripe persimmon. Some growers freeze khalaals to remove astringency. Barhi and Desert Gem are two kinds that are very good in their natural, unfrozen state. Khalaal dates are cut and packed on the string they grow on. Given the proper conditions they will continue to ripen into the rutab stage.
In the rutab stage, soft date varieties can be very juicy. This is called "wet" in North America. They can be harvested like this, but are very delicate and need to be handled very carefully.
If allowed to hang on the trees another two to three weeks they will go into their tamr state and are self-preserved. The tamr dates are still soft, but have a lower moisture content than rutab. Most dates are harvested in the tamr stage.