The Arboretum at ASU Date Palms

ASU has the largest date palm collection of any public garden in the country with more than 40 date palm varieties.

The entire Arizona State University Tempe campus is a designated arboretum. The campus is an oasis of plants from around the world.

日本一本道a不卡免费Probably the two hardest parts of growing date palms is obtaining a quality, named cultivar offshoot and getting the shoot to root and grow. Growing palms from shoots inherently involves a certain amount of random chance. Sometimes a perfectly removed shoots with roots will die.  Sometimes undersized, damaged, or rootless shoots will grow. However there are some cultivation methods that increase your chances of getting a shoot to root.

日本一本道a不卡免费It is worth noting that there is a fair amount of “horticultural folklore” about how to treat new shoots. The volunteers at the Polytechnic Date Palm collection have tried many of these tricks. The following article represents our observations of what works the best.

A date palm shoot is effectively a large cutting from the parent plant, so a lot of the strategies for propagating other plants by cuttings also applies to date palm shoots. The most immediate problems (and causes for shoot death) are drying out of the shoot and rot at the cut location. After it makes it past the first month, then over-exposure to heat and sun seem to be the main cause of death. Some shoots will die even if you do everything correctly. Even the date palm volunteers at Poly only have about 70% success rate.

The key steps in getting your shoot to grow are:

  1. Obtain your shoot at the right time of year. 日本一本道a不卡免费Date palms generally are in active growth between about April and September in the Phoenix area. You want to obtain your shoot during this time. The plants are dormant during the winter, so any shoot removed then is just going to sit there for a few months until it warms up. This also increases the risk that the new shoot will rot in the cool and damp weather of winter.

  2. Pick a variety that is easy to root. Some varieties of dates are famous for easy-to-root shoots. These included Barhee, Halawy and Deglet Beida. Other varieties are known to be “problematic”, such as Thoory and Empress.  When starting growing dates, choose one of the varieties that is easy to grow.
    Shoot growing suggestions:

  3. Tie up the leaves on the shoot Tie the leaves into a tight bunch. This protects the young interior leaves from the elements. The new growth will push out of the top of the leaf bunch. 

  4. Trim the leaves Cut all the leaves back to about 2 feet above where the leaves emerge. Cutting the leaves back reduces water loss from the shoots that would cause them to dry out. Remember that your new shoot will have few if any roots to replace lost water. Trying to maintain a large leaf area just increases the chances that the shoot will dry out and die.

  5. Plant your shoot quickly. Get your new shoot planted as quickly as possible. The more the shoot is exposed to the elements, the more likely it will dry out. If you cannot plant it immediately, then soak the shoot  base in a bucket of water for a day or two until you can plant the shoot. 

  6. Dust the shoot cut with fungicide. Just prior to planting the shoot, dust the cut point of the shoot with a fungicide or rooting hormone. Rooting hormone mixtures often contain fungicides. The goal is to prevent rot from starting at the cut mark until it has a chance to heal. Rot at this large trauma on the plant is a common reason for shoot failure.

A tied group of leaves on a shoot. The extension of the interior leaves suggest that this shoot is taking.

日本一本道a不卡免费Growing date palms is a long-term investment and you need to plan ahead about where you want the palm to be located. Here are some considerations about where to plant a palm in your yard.

  1. Do not plant a palm in areas with a lot of foot traffic. Date palms are spiny and their leaf tips are sharp, so plant them away from paths or patios where people are likely to brush into them. Avoid place where kids play since they may run into them and inflatable balls don’t tolerate run ins with date palm spines. Lastly, the palms will drop fruit that can make a sticky mess (although you should bag the fruit). The back corners of the yard are good spots for palms. You can expect that the crown of a date palm may reach as far as 10 feet from the trunk.

  2. Sadly, people sometimes steal fruit from trees in front yards and dates are a high value crop. This means it may be a good idea to keep the better date palms in the back yards or behind fences. The front yard is a good place for male date palms, but keep them away from the sidewalks.

  3. Check to make sure that date palms are not planted over or near in-ground utility lines. This includes phone, cable and irrigation lines. Date palm cultivation requires frequent digging around the base of the palm with heavy tools that can easily cut these lines.

  4. Consider giving the palms the sites that are too hot or dry for most other plants. Very few plants can take the west side of the house that is in full sun, but date palms can take the heat. Basically, there is no place too hot for a date palm; just make sure it gets enough water for the first few years until it is fully established.

  5. 日本一本道a不卡免费It may seem obvious, but don’t plant palms under power lines. The palms will get tall someday and interfere with the power lines.

At this point you have a choice: you can either plant the shoot in a pot or directly in the ground. It appears that starting shoots in pots has a greater success rate. Transplanting a shoot from the pot to the ground is easy and safe and not a source of mortality. However, the transition will shock the plant and cause it to stop growing for a few months. Plants that are started in the ground will need watering less frequently and they will grow faster in the absence of transplant shock.

Pot Planting Instructions

  1. Select a pot that is about 6” wider than the widest diameter of the shoot. In general, 15 gallon pots work well for most shoots and they are still relatively mobile. The 24” box also works, but they are hard to move by a single person. Five gallon pots work well for small shoots.  The plants are not going to stay in these pots for very long, so you don’t have to allow for a lot of room for future growth.

  2. 日本一本道a不卡免费Use a quick draining mineral matter soil like sand, perlite and/or clay. Do not add potting mix, compost or other organic material that may be a source of rot. You want the soil to be porous and airy to ensure the soil does not go anaerobic. Pure sand works alright, but a little clay (i.e. standard Phoenix dirt) adds some nutrients. Using pure sand can cause the sand to leak out of the holes in the pot. If this is a problem, then put paper towels over the holes to retain the sand.

  3. 日本一本道a不卡免费Place the shoot so that the widest point is about 2/3 high in the pot. Add soil until the widest part of the shoot is at the soil level. Water the shoot in and add more soil if needed.

  4. Put the shoot’s pot in dappled shade. Remember that the shoot was shaded by the parent palm where it was previously growing. Pick a spot where the shoot will never get full sun (e.g. under shade cloth, under a tree, etc.). Even full shade may work if it is bright shade. Ideally, the location should be a cooler microclimate in the yard.

  5. Water the shoot about every 3 to 4 days in summer and once a week in winter.

  6. Fertilize the shoot with a weak water soluble fertilizer (e.g. MiricleGro) every few weeks during the growing season.

  7. After about the first week, re-trim the leaves so that all the leaves end at the same level. This does not help the shoot to take, but rather helps to indicate when the shoot has taken. The shoots tend to grow a little in the first week after being removed before the shoot realizes it is now separate from the parent plant. It will then stop growing. This is when you want to trim the leaves to an even length. Any additional growth after that suggests that the shoot is taking. 
    Once the interior leaves in the bunch have extended about 10” beyond the outer leaves (count only live leaves; dead leaves shrink), then the shoot has taken.

  8. 日本一本道a不卡免费Date palm shoot are slow to grow and it will often take a year for a shoot to grow.

  9. Once the shoot has taken, then the pot can be moved out into more sun. It is suggested that it is gradually moved into more sun to ease the transition shock or reduce the potential for sunburn on new foliage.

  10. Give the plant a full growing season before transplanting it into the ground. Expect that a palm transplanted will go through a transition period and it will stop growing for a few months.

Ground Planting Instructions:

  1. Select a spot where the palm will be grown. If you want the palm to grow in a particularly hot and harsh location (west side of house, next to road, etc.) then you may want to start it in a pot first. Make sure it is in a location where it can be easily watered. Also make sure that the palm is NOT over in-ground utility lines. Date palm cultivation involves a lot of digging around the palm with heavy tools as you remove shoots from the palm in the future.

  2. 日本一本道a不卡免费Dig a watering basin for the plant. The watering basin should be about 4” to 6” deep and 24” to 36” wide. The basin should be below ground level so water will flow into it. Date palms like being flooded every once in a while./p>

  3. 日本一本道a不卡免费In the bottom of the basin, dig a hole for the shoot. The minimum requirements is to dig a hole that is deep enough to plant the shoot to the maximum diameter of the shoot. Some Poly collection volunteers like to dig a much larger hole and then fill the hole with pure sand. The sand is quick draining and is porous and allows the air to penetrate the soil.

  4. Plant the shoot so that the widest part of the shoot is at soil level.

  5. Water the shoot in and add more soil if needed.

  6. 日本一本道a不卡免费Shade the shoot with open weave burlap cloth (sold in garden centers). Cover the entire shoot with the cloth and leave it on the shoot for the first summer and winter. The cloth can be removed once the shoot has taken. The cloth is designed to protect the tender shoot from the harsh sun and winter cold.

  7. After about the first week, re-trim the leaves so that all the leaves end at the same level. This does not help the shoot to take, but rather helps to indicate when the shoot has taken. The shoots tend to grow a little in the first week after being removed before the shoot realizes it is now separate from the parent plant. It will then stop growing. This is when you want to trim the leaves to an even length. Any additional growth after that suggests that the shoot is taking.

  8. Water the shoot every 3 to 4 days during the summer and weekly in winter.

  9. Once the interior leaves in the bunch have extended about 10” beyond the outer leaves (count only live leaves; dead leaves shrink), then the shoot has taken. You can remove the shade cloth at this point. The watering frequency can be decreased to once a week in the summer and once every two weeks in winter.

  10. A year after the shoot has taken, then the watering schedule can be reduced further to the same frequency as Citrus. Date palms love flood irrigation schedules and/or lawn watering schedules.

  11. 日本一本道a不卡免费For best results, fertilize the palms three times during the growing season (e.g. April, June August) with either palm fertilizer or Citrus fertilizer. The palms do surprisingly well without any additional fertilizer, but you get faster growth (and probably more fruit) with fertilizer.

A date palm nursery under the dappled shade of a tree.

Three date palm shoots 15 months after being removed and planted directly in the ground.

Shoot after 26 months

日本一本道a不卡免费Shoot after 36 months