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Underhill Deep Drip Stake 36" | A-DD36

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Underhill Deep Drip Tree Watering Stakes

  • Underhill Deep Drip Stake (A-DD36)
  • Length: 36 inches
  • Fits standard 1/4" drip line

Deep Drip Tree Watering Stakes aid in the watering and fertilization of your trees at the roots, in addition to better aerating the soil with oxygen. Deep Drip will deeper saturate the ground around your tree allowing the roots to grow deep and strong instead of horizontally at the surface, possibly resulting in exposed roots. This device is designed to work with a garden hose, flood irrigation, or in conjunction with your automatic landscape drip system.

Your standard 1/4" drip line easily connects to the Deep Drip spike.And you can also add fertilizer into the shaft to continually direct nutrients to the root zone. Whether you have fruit, oak, or palm trees,start watering your trees where the roots are and where you want them to be. Roots tend to follow the water source, so show your roots the path to grow deep. When you can get water underground faster, you can water for shorter periods, while practicing sensible water conservation. Our Patent Pending Deep Drip tree root watering devices are made in the U.S.A. and come in three sizes: 14, 24, and 36 inches.

Our Deep Drip tree root watering devices come in three lengths: 14, 24, and 36 inches. The 14 inch unit is perfect for small trees and shrubs with shallow roots, like rose bushes,ornamental trees, or in commercial use for trees still in boxes. The 24 inch unit is used for your average trees, while the 36 inch unit maybe used for palm trees and deeper rooted trees.

  • A-DD14
  • A-DD24
  • A-DD36

The devices are constructed of sturdy ABS and PVC. The reinforced tip and cap are made from ABS, while the upper shaft is made from Schedule 40 PVC. There are multiple holes in the bottom half of the spike, internally covered by a mesh filter that allows water to flow out, but keeps dirt from getting in, settling,and clogging the tube. The UV protected cap has multiple functions, a sit acts as a Protective/reinforced cover when hammering in to the ground, keeps rocks and leaves from entering the shaft, and holds the inch drip line securely in place. And in many parts of the country, the cap also protects the emitter head from squirrels or other animals.

Periodically, as the tree grows and roots extend farther away from the tree, repositioning the device beneath the outer edge of the tree's canopy is recommended. The upper shaft has two holes at the top so the user can remove and replace the unit as needed. Just insert a screwdriver or like tool through the holes and pull up.

Features & Benefits

  • When connected to a drip line, Deep Drip is one of the most effective devices to get water, oxygen, and fertilizer to your tree's roots quickly and efficiently.
  • Deep Drip will conserve water as 100% of the water directed tothe tree is going deep into the ground, without losing any water to evaporation or run-off. And the internal filter keeps dirt and rock from entering the device.
  • Deep Drip will promote deeper roots as they will follow the deeper watering.
  • Furthermore, Deep Drip will guard against visible roots rising to ground level for water. Water dispersed solely from a standard drip-line can permeate only so deep into the ground.
  • Tree fertilizer can be fed into the shaft, having water pass through the granules and carry the nutrients into the soil and directly to the roots, thus promoting a healthier tree and root system.
  • Fertilizing within Deep Drip, instead of through an emitter, guards against clogged emitters or tubing, with no waste.
  • When inserted on a slope , Deep Drip prevents water from running down the hill away from the tree while eroding the landscape. The tree will benefit from getting more water into the ground and to the roots,while less water will be wasted down the hill.
  • When considering the costly replacement of a dead tree,purchasing and installing two or three Deep Drip devices per tree is a smart investment for homeowners and HOAs, as well as landscapers and nurseries who guarantee a tree's survival.
  • Deep Drip is the most hassle-free, maintenance-free tree deep-watering device on the market that once you place it into the ground, you'll never have to worry about it again. No need to pull out the hose, turn it on, and remember to turn it off, as Deep Drip works with automatic drip systems.
  • When tree owners water and feed more effectively , trees have a better chance of surviving after being planted. And throughout the life span of the tree, it will receive continual deep watering and fertilization as a healthy lifetime solution.
  • For existing trees, the 'pointed' end and reinforced cap allows for driving into the ground with a sledge hammer when digging a hole is not a consideration.
  • The shaft can be completely buried and out of sight or left with the UV Protected cap above ground.


There are two ways to install the Deep Drip tree watering stakes. Either by inserting the units during new planting or by driving the unit into the ground (while wearing protective eye wear, of course) around an existing tree. The reinforced pointed tip and specially designed cap are engineered to take quite a beating.

During one test in extremely hard ground, our researchers used a 3-pound sledge hammer, pounding the device 484 times to get a 36" unit into the ground. Obviously, this was very hard ground and most installations may only require a couple dozen hits, although we mention this to show you the strength and durability of our units.

Designate a location for the Deep Drip tree root watering tool installation. Choose a spot free from underground lines and pipes; select the location that is approximately half way between tree trunk and outer edge of tree's canopy. Newer trees are recommended to have 2-3 units on opposing sides or surrounding the tree base.Older, more established trees may need as many as 5-6 stakes to fill the circle around the tree (image below).

During New Installation of Tree: After tree has been placed in the hole, insert 2-3 Deep Drip units vertically in the hole surrounding the tree before back-filling with soil. The top of Deep Drip can either be above ground level or below ground, depending on your preference.

Installation at Existing Tree: If you are installing Deep Drip at an existing tree where a hole no longer exists, then you will need to either dig a hole or drive Deep Drip into the ground manually. To drive into the ground using a sledge hammer, place slotted end cap on the open end of the shaft without the drip line inserted (Fig. 2). Always wear protective eye wear. Do not directly hammer the 'uncapped' end into the ground as this could break or destroy the shaft. A three-pound sledgehammer is recommended to drive the unit into the ground. Drive Deep Drip completely into the ground or leave the cap visible, whichever is preferable.

Troubleshooting: If soil is too dense, water the area around the tree and use a soil softener to soften the ground before inserting. Also recommend to insert stake or rod into the ground and remove to clear pathway for unit. Drilling into the ground using an auger bit is another way to clear pathway for unit. Again, make sure you are aware of any underground lines or pipes and do not insert where they may exist.

When positioned in the ground, remove cap and insert end of existing drip line and emitter into the shaft aligning the drip line with the slot in the cap (Fig. 3). Re-install cap to secure drip line and stop excess debris from entering shaft. We also recommend to place an emitter at the surface in addition to the Deep Drip units(as seen in the illustrations on the Home Page).This will ensure that the shallow roots will get the much needed water as well as the deeper roots.

When using with a hose, we recommend that you create a small berm around your tree to hold in the water and prevent run-off. Bury 2-3 Deep Drip stakes equally spaced within the berm around the tree. Remove the caps from the stakes; lay the slow flowing hose within the berm and the water will saturate the shallow roots near the surface and eventually flow down into the stakes to water the deeper roots. The harder the ground, the slower and longer the flow you will need to saturate the root zone.

Idea: Pour granulated tree fertilizer into shaft after positioning in ground. Water will pass through and slowly dissolve nutrients, feeding the tree at the roots.

To Remove: Insert rod or standard screwdriver through the two holes in the main shaft just below the cap. Slide the rod through the shaft and pull up (Fig.4).Slightly twisting the shaft maybe necessary for easier removal.Every six months it is recommended to rotate the unit 360 degrees while in the ground to keep the small roots from entering the shaft.Just insert a screwdriver or rod and twist.

Watering and Fertilization: Ask your local lawn and garden professional for recommendations on watering levels, emitters,and different types of tree fertilizer, specific to your tree's needs.

Related Articles & Videos



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Underhill A-DD36 36 in. Deep Drip Tree Watering stake
the question asked on how do you remove this stake. the ans is I have never removed one . I use the ones I placed regularly to conserve water and to build root structure.. trees watered in a lawn do not build a deep root structure and therefore are easily uprooted by wind.
April 19, 2016
great product
after doing some research, I decided to use this product and glad I did. easy to install and works just like discribed
October 18, 2017
over 2 years ago
Hit with mallet x 5, water (repeat) ??
Good so far. I converted my above ground drip irrigation, to deep root drip with this. My trees were transplanted less than 6 yrs ago. The design seems good. Multiple spikes per tree are recommended by MFG, which can add up to a pricey conversion. I'm hopeful that this works. If I didn't wait too late to convert & my trees survives the summer heat, I'll have to change this to a 5 star review.
August 22, 2018
1 year ago
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 8 questions Browse 8 questions and 9 answers
Why did you choose this?
SprinklerWarehouse.com Store
Existing 20 year old tree needs deep watering from existing dripline
Chris on May 31, 2018
wanted to try it
K D on Apr 29, 2018
Existing 20 year old tree needs deep watering from existing dripline
Chris on May 31, 2018
It looks like it will work to irrigate my trees. But what do I know, I'm not a horticulturist.<br />"You can lead a horse to water but you can't make it drink."<br />"You can lead a horticulture but you can't make her think!"<br />...a little gardening humor for you.<br />Now, aren't you glad you asked for my input.<br />-Rich-
S Y on May 15, 2018
wanted to try it
K D on Apr 29, 2018
I'm lazy didn't want to build them.
William K on Mar 2, 2018
Need watering spikes for patio trees and patio palms
L D on Jun 9, 2017
It looks like it will work to irrigate my trees. But what do I know, I'm not a horticulturist.<br />"You can lead a horse to water but you can't make it drink."<br />"You can lead a horticulture but you can't make her think!"<br />...a little gardening humor for you.<br />Now, aren't you glad you asked for my input.<br />-Rich-
S Y on May 15, 2018
I'm lazy didn't want to build them.
William K on Mar 2, 2018
How do you know to use a 24.5" or a 36"? I will be planting a large (the biggest I can find) orange tree.
G H on Apr 2, 2015
Underhill Deep Drip Stake 36
Underhill Deep Drip Stake 36" | A-DD36
Underhill Deep Drip Stake 24.5
Underhill Deep Drip Stake 24.5" | A-DD24
I have a large ficus tree that has roots coming up through the lawn and has begun to move affect my sidewalk. I have been I need to water the roots more effectively. Will this product work for that purpose? Also, how many spikes will I need?
Gerry S on Sep 10, 2011
need to know if this product can be connected directly to a garden hose or does it require a special fitting?
A shopper on Aug 21, 2011
BEST ANSWER: There is no need for special fitting.I personally don't connect the water hose directly,because I have several stakes, which water a few trees ,so I use a 3/4 " poly line with 1/4" lines from the poly line to each stake.This combination works very well for me,because I don't have to move the water hose to each tree stake. The stakes are a little expensive in my opinion, but they are very useful for tree watering
I have a river birch planted in a dry area that needs deep watering. How does this product work?
Karen R on May 8, 2011
BEST ANSWER: Depending on the size you purchase will get water to desired depth, by using gravity and capillary action. The small micro tube that supply's the water fills the device ( places 1' to 2' in from the edge of the leaf canapy where the roots are most active and newer. Larger trees will need 6+
I want to deep irrigate and feed both a Canada Red Cherry and a Spring Snow Crab. Is this irrigator a good option?
Patricia N on Jun 17, 2017
Has anyone used the A-DD36 in a pecan orchard?
Ken W on Dec 30, 2016
BEST ANSWER: Sorry no I have not
How to use this item with Underhill Deep Drip Tree Watering Stake? Our soil in Lost Wages, NV is similar to type II used for underlayment of concrete but with the added benefit of numerous rocks and stones.Once you pound this tool into the ground I don't see how you would easily remove it. Maybe you could make a video on how to use this tool under these conditions.
Peter H on Apr 19, 2016
Underhill Deep Drip Stake 36
Underhill Deep Drip Stake 36" | A-DD36
UPI SIT36 36 in. Forged Steel Tree Stablizier Install Tool
UPI SIT36 36 in. Forged Steel Tree Stablizier Install Tool
BEST ANSWER: I have the same type of soil in general. Clay and rock. I can't really answer the question as how to remove the tool as I did not know about it. So my question would be the same. I could not even begin to get the stakes into the ground without breaking them so gave up on them. This is not a negative comment on the product as I think it is a great idea. You just need to check out the soil. It really fits our needs here in Ca. as we have been in a drought going on 4 years plus.

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