Sunday, August 17, 2014

How to: Grow Date Palms from Seed

Phoenix is a genus in the family Arecaceae which is composed of about a dozen species. The most economically important of which is Phoenix dactylifera, the true date palm. Fruits of the date palm contain very high sugar content and are prized for the energy they provide.

Date palms generally require very warm and sunny summers with mild winters, typical of many regions of the Middle East. Dates are commercially cultivated in the Middle East, parts of Africa, many islands and subtropical locations, but also in the United States. Dates are cultivated commercially in many states including California and Arizona. In order to ensure successful harvests, dates must be grown in arid regions that have hot summer temperatures and only mild freezes in the winter months. On top of that, fruit production requires a lot of water, despite the fact that dates can withstand long droughts.


Date trees are versatile, serving as much more than a shade tree that provides fruit. Sap can be tapped from the trees, which can then be used as a sweetening syrup or fermented into an alcoholic drink. The leaves are used for a variety of purposes such as roofing for houses, and crafts such as baskets. Seeds can even be used as a feed-stock for animals.

There are over one hundred cultivars of dates grown around the world and the differences between them can be quite stark. For instance, the Deglet Noor date is generally light in color with firm flesh where as Medjool dates have a dark color with thick and soft flesh. Some dates are small, some large, while others are moist with sugars and syrup others can be dry to the touch. Quite possibly my favorite dates are the Jumbo Medjool dates which are especially large compared to typical Medjool or Deglet Noor dates.


Growing date palms from seed:
This method is quite easy but actually yielding fruit from your trees will be a bit more challenging. To grow a date palm simply eat a date, remove the seed and wash it clean of any excess flesh.

Next soak the seeds in water for at least 24 hours (or 48 hours), which will allow the strong seed coat of the date seeds to imbibe water.

There are many methods for germinating date seeds, but there are two easy methods for most date seeds. The first is to sow the date seed (rough side down) about 1" into a small pot filled with soil. Lightly water the soil occasionally ensuring moisture at the seed's depth, while being careful not to over-water the soil.

The second method is to wrap the date seeds in a slightly moist paper towel and put them in a plastic bag. Place the bagged seeds in a warm place, at least 75°F and small white roots will begin to appear from one side of the date seeds. The germinated seeds may then be planted in a small or medium sized pot filled with a palm or cactus potting soil.

Date seeds are really picky when it comes to moisture, they want to be only slightly moist so be sure not to over water the seeds. Other germination methods work better for tricky seeds, and these include the incorporation of sand and vermiculite to help regulate the moisture of the soil.

Potting soil for date palms:
Palm or cactus potting soil mixes are a good choice for planting date palms in, and they are usually available at home and garden stores. Alternatively you may add sand and/or vermiculite to a generic potting soil (in a 1:4 or 1:3 ratio) to provide good aeration and drainage. Adding peat moss to the soil will help the soil retain moisture if it is draining too well. Most palm or cactus potting soils have a good mixture of sand, vermiculite, perlite and peat moss and will be the most suitable for date palms.

Once you have a date palm seedling established, you must cater to its growth by transplanting it gradually to larger and larger pots. Transplant your date palm when you notice that it is outgrowing its container or growing roots out from under the container. Be sure to water the palm well before and after transplanting and avoid transplanting into a significantly larger pot. Alternatively the palm may be transplanted into the ground if your climate supports its growth. Otherwise date palms may be kept in large pots outdoors, on a porch or somewhere receiving maximum sunlight. It may be possible to keep date palms indoors near a window that receives direct sunlight, although its growth will likely be severely hindered.

Date palms are dioecious, meaning that each plant is either male or female. Females are more desired because they will bear fruit, while the males only provide the pollen to fertilize the females. This means that only one male plant is needed to pollinate many females. The pollen grains of date palms are small and can easily travel by wind to pollinate the females, but commercially it is hand pollination that is the method of choice to ensure maximum fertilization.

Growing date palms by seeds results in plants that are not true-to-type, meaning the seedlings will develop into palms with fruits that may be smaller and of lesser quality than the parent. On top of this, only about half of the seeds that germinate will be the desired females. Therefore vegetative propagation is the preferred method of many commercial farms and nurseries. This can be done through tissue culture in a laboratory setting or by offshoot rooting of young date palms.

Date palm propagation by offshoots:
Young date palms, about ten years of age, will begin to send offshoots from the basal portions of the trunk. These offshoots are directly connected to the parent plant, and thus receive all of their nutrients and water from the parent. Overtime they will develop roots that will bury into the soil to support their independent growth. This may be facilitated by building soil up around the offshoot if it appears close to the parent trunk. Over time these may be severed from the parent plant and potted in a process that should only be done by experts to ensure success. Although this is a long and time consuming method of propagation, it results in true-to-type clones of a female plant that will have a head start over date palms started by seed.

Above are ripe fruits of the Silver Date Palm (Phoenix sylvestris) which is a date palm with a sweet sap that is used to make palm wine. The fruits are edible but have only a small layer of flesh, though I find them to be delicious.

This is an inexpensive box of Iranian dates the cultivar of which I do not know. There is a huge difference between these low quality dates and those that fetch over a fifty dollars a kilogram. I found these dates to have a soggy texture and a thick outer skin.

Green, firm immature fruits can be seen on this date palm (Phoenix dactylifera)

A closeup of this date palm (Phoenix dactylifera) shows mature offshoots that were allowed to grow, and the many small knobs from offshoots that were cut back long ago. Notice the roots that emerged from the old offshoots.