It occurred to me that the traditional way of growing avocado seeds in a tiny cup of water could be improved on. It was a nuisance having to continually top up the tiny water cups. This instructable is about how I came up with a more efficient way.
Step 1: Materials and Tools
The materials used are one tray and a piece of Styrofoam. Both items were in my extensive collection of 'things that might come in useful some day' so cost me nothing to acquire. The tray measures 9" x 7" x 3". Of course many different sizes of tray would suffice, larger or smaller, depending on your particular needs. Ideally a transparent tray would provide the benefit of seeing the water level from a distance.
1 1/2" Hole Saw
All common items in most tool kits with the possible exception of the hole saw but this instructable can still be made without such an exotic tool. I will explain how further on.
Step 2: Objective and Method
My aim was to have a larger water trough with a floating element to hold the avocado seeds that would also act as a barrier to water evaporation. The seeds needed to be able to access the water but not to be fully immersed in it. Because Styrofoam floats it ensure that the seeds are always in contact with the water as the level of water goes down. In fact they need only a fraction of inch of water to float freely. The end result is constantly watered seeds that need water replenishing only after a much longer time than when they were in individual plastic cups and needed watering most days.
Essentially, my aim was to keep it simple and cheap. With just two parts to this, three if you include the use of cocktail sticks to support the smaller seeds, this solution is very simple. No money was spent at all because I pulled the materials from my extensive collection of 'things that might come in useful some day'. If you do not have such a collection I estimate that this could still be made for just a few bucks. The project took very little time, less than half an hour including the time taken to gather the materials and tools.
Step 3: Making the Avocado Seed Tray: 1
Having measured the tray and the Styrofoam it was necessary to cut the Styrofoam down so that it would float freely in the tray. This I did with a pair scissors.
Step 4: Making the Avocado Seed Tray: 2
Next I marked roughly where the holes needed to be drilled. In this example the plan was to put a hole near each corner with a couple in the middle as well. Other patterns may be used bearing in mind that the weight of the seeds needs to be balanced to ensure proper water distribution for all seeds.
Step 5: Making the Avocado Seed Tray: 3
After measuring the diameter of a couple of seeds I figured that the hole the seed would sit in needed to be large enough to allow the bottom constant access to the water but not so large the seed would slip through. The drill I chose to use was the 1 1/2" hole saw tool. The drill was operated at low speed to carefully and gently cut through the Styrofoam without stressing and damaging it. It is important to properly support the Styrofoam (which I did with my hand) to maintain its integrity. If you use this method be very careful not to cut your hand as that is likely to hurt! In fact, it may well be possible to adequately support the Styrofoam by placing it on water and holding it with all of your digits kept well away from cutting edges. Don't drop the drill in the water either ...
If you do not have a hole saw in your tool collection that is not a problem. Determine the size of the holes you need and make a paper template. Place the template on top of the Styrofoam, mark the circles with a pen and cut them out using a craft knife.
Step 6: Making the Avocado Seed Tray: 4
Add water to the tray, place the Styrofoam on top and then add the avocado seeds. I made the holes large enough to accommodate the larger seeds. To stop the smaller seeds falling through I used a cocktail stick cut into three and placed at intervals around it. The sticks rest on top of the Styrofoam preventing the seeds falling through.
Step 7: Completed Avocado Seed Tray
And there it is sitting outside in the sunshine topped up with enough water to keep the seeds happy for quite a while.
Many improvements can be made to this design I'm sure. For example using a piece of Styrofoam that fits more snugly and using a transparent tray. So, over to you now. Please share your examples of the Avocado Seed Tray on instrucables and add links to your pages in the comments.