Pot Growing Without Pots

by

Harold Baker

4445 Arlington Park Dr.

Lakeland, FL 33801-0545

Ph 863-667-0308

 

            There was a period in my life when I was willing to put forth any amount of effort to raise good roses.  In recent years my thoughts have turned to how can I spend a minimal amount of time in the garden and still grow good roses.  I don’t mind planning and executing projects such as preparing beds, installing watering systems, and selecting the best varieties for my small garden.  What I don’t like to do is spend time on repetitive tasks like spraying, fertilizing, dead heading, watering, weeding, etc.  The quest for an easier way to grow high quality roses has caused me to progress through six different methods of growing minis.

            First I grew minis on their own roots in the ground in the same manner as all other rosarians did at that time.  The second phase was to grow minis on their own roots in very high raised beds.  To my knowledge I was one of the first to do this in colder climates such as we had in Illinois.  The minis loved it and I enjoyed them much more when they were at a height where I could see the blooms closely without breaking my back.  It made taking care of them much easier.

            I entered my third phase after moving to Florida.  I started growing my minis on their own roots in 7 1/2 gallon pots in soilless mixes (Fafard #2 & #3B).  The pots were buried in the ground.  The bushes grew more vigorously in these mixes than in anything else I had ever tried, and if I wanted to give a plant away it was really easy to pick up the pot and hand it to them.  However, there were a few drawbacks.  The plants grew so well and threw up so many new shoots that it made it difficult to water the pots except by hand.  It was particularly difficult for an automatic system to wet the entire surface of the pot, which was something I desired.  The dense mass of shoots also made spraying for disease and controlling spider mites more difficult.

            Therefore, my next phase was to solve this problem by grafting my minis onto Fortuniana rootstock.  I made the grafts about 10 inches above the ground level.  This really helped.  By eliminating all the stalks at ground level, except the one for the rootstock, a Dramn watering system once again worked fine.  There was not as great a potential for blackspot as before since all the foliage was well above any splash zone.  Reaching underneath the foliage to spray and water wand was a snap. The stem length is probably twice as long as when grown on own roots.  Foliage size is normal.  Bloom size is related to how much one fertilizes.  I am having to learn that my minis don’t need to eat every time that I eat.

            But I had a new problem to solve.  What is the best way to grow minis on Fortuniana?  This led to phase four and five.  The literature says that most of the Fortuniana roots are in the top 10” of soil and that they are very long.  Some have recorded lengths of 16 ft.  It seemed unlikely that they would be happy in a pot but one can never be sure.  I ran a test to find out.  Whenever I grafted a variety I always made two.  One of these I planted in a carefully prepared bed of sand, manure and all the other goodies.  The other one went to my good friends Bob and Angie Heatwole to be grown in 10 gallon pots containing my favorite soilless mix (Fafard #3B).

            I have discovered several things as a result of these tests.  The roses in pots in the soilless mix jumped off to an early start. They quickly outgrew the ones grown in the ground just as they had done previously when the minis were on their own roots.  Roses grown in Central Florida never really stop growing.  They just slow down during January and February.  Would the roots quickly fill the pot and choke off growth while the ones in the ground took off like gangbusters? No, it didn’t happen that way.  However, the ones in the ground did, after a much slower start, also began to turn in a very good performance.  But they exhibit more variability in their growth than those grown in pots with a soilless mix.  I would say at this time about 1/3 of the in ground bushes are larger and about 2/3 of them are smaller than those grown in the pots.  Those in the pots are much more uniform in size.

            I would rate the performance of those grown in the ground soils as very good and those grown in pots with the soilless mixes as excellent.  Analyzing all this data lead me to my present phase #6.  In this method I am trying to obtain almost all the advantages of both the in ground and the soilless mix in a pot method.  Basically, I reasoned that it was not the pot itself that made the minis grow so well but that it was the soilless mix within the pot.  Since I put the pot in the ground anyway to maintain a better temperature for the root ball, why not just dig a hole in the prepared bed the size of the pot and fill it with the soilless mix that the roses seemed to love.  It would be easier to water the surface of the bed than it would be to water inside a pot and I shouldn’t have to worry about the minis getting root bound.  I could make the “pot” large enough that I could grow a large bush even if the roots did not grow outside the “pot”.  On the other hand, if an adventurous root wanted to leave the soilless mix and venture out into the prepared bed, there would be no pot wall there to stop it.  This method would also give me the freedom to not only decide the volume of the “pot” but the shape of it as well.

            The 10-gallon size seemed to be working great for minis so I decided to stay with that volume.  However, if most of the Fortuniana roots want to stay in the top 10 to 12 inches of soil it would appear to be a more efficient use of the volume if I designed my “pot” to be only 11 inches deep but with a larger diameter than it would have if I used the dimensions of a regular 10 gallon pot.  The diameter I am using for the minis is 17 inches.

            I use the following procedure.  I take a bamboo stick and loop one end of a piece of twist-tie around it and loop the other end of the twist-tie around a pencil 81/2 inches away.  I stick the bamboo stake in the ground where the center of the bush will be and scribe a 17” dia. circle in the dirt with the pencil.  My standard garden shovel blade is 11 inches tall, so I don’t have to measure the depth of the hole.  Just dig it out to the full depth of the shovel.  I pour the Fafard #3B soilless mix into 5 gallon buckets, which are then filled with water.  I want to make sure the sphagnum peat moss in the mix is completely soaked before it goes in the hole so it will not try to pull moisture from the roots.  I only put a thin layer of mix in the bottom of the hole since the 2 or 3-gallon pots that I am transplanting from are almost as tall as the hole.  I mix 1/2 cup of superphosphate uniformly throughout this bottom layer.  I then make a little pocket just at the edge of where the 3-gallon plant will sit and fill it with another 1/2 cup of superphosphate without mixing.  Then I spread a thin layer of Milorganite over the entire surface and set the root ball directly on it.  Wet mix is added around the root ball to within 1/2 inch of the ground level.  1/2 cup of Osmocote is uniformly spread across the surface and covered with another 1/2 inch of wet mix.  Water well a couple of times to settle everything in and add mulch.

            The results are outstanding. Do I think there is a still better way?  Absolutely!  There is always a better way, otherwise I wouldn’t be on my sixth improved version.  If you know of a better way, or have a suggestion on how to improve this method, please share it with me.  Write, telephone or if you want to do it by E-mail contact me at BAKEinFL@aol.com.  BAKEinFL is in recognition of the fact that Lakeland has the unfortunate distinction of being the hottest city in peninsular Florida.

            Incidentally, this method works so well that I now use it for all new plantings of my large roses.  The size of my large rose “pot” is 11 inches deep and 24 inches in diameter and I use one cup of Osmocote.  The results look equally great with the big roses.


CONTRIBUTORS

 

POT GROWING WITHOUT POTS

Harold Baker, Lakeland, FL.

Harold Baker is a Life Horticultural Judge and Consulting Rosarian  His winnings include Canada’s Paul B. Saunders National Challenge Class as well as the HT Queen and the Best Rose in the Show at the 1985 International Rose Show.  He has also won the National Horace Mc Farland, the Earl of Warwick Urn, and the Jan Shivers, Ralph Moore, and Robert & Mildred Lawton National Miniature Trophies.

 

page updated: Saturday, September 14, 2002