After receiving a good hard frost we decided to dig up our Georgia Jet sweet potatoes. We are tickled with our harvest that ended up filling a wheel barrow. Not sure what the total weight as we just didn’t weigh them.
They were growing in a 4 foot wide and 15 foot long grow box that was filled with a mixture of sand and sawdust. Digging them was very easy, we used only our hands to sweep the sand and sawdust out of the way to expose the sweet potatoes.
You can see the outline of the growbox in the picture below. As you can see, they grew like mad. Next year I will prune the vines as they grow beyond the box.
This was the average size of what we harvested. They grew easily in our sand and sawdust and weren’t mishappen.
This is the completed harvest here in the wheel barrow. Not a bad haul for a 4 x 15 foot growing area!
We now have 32 Georgia Jets sweet potato slips in our 4′ X 15′ grow box. I’ve never knowingly eaten one before but wanted to give them a try. This is also our first year growing any sweet potato in a grow box with a sand and sawdust growing medium. Last year digging potatoes in the heavy clay soil was a lot like work. This year it should be so easy.
I’m still working on clearing the grass and weeds around the grow box. When finished there will be a bare dirt border 5 feet from the box. By doing this it helps keep insects away from our vegetables. It also helps keep weeds from getting into the grow box and competitimg with the vegetables for the water and fertilizers as well as space and light.
With the grow boxes filled with medium and seedlings transplanted our next project was the completion of the automated watering system. Lesson 16 in the MGC book, page 125, covers the construction details of the automated watering system. Three holes were drilled every 4 inches of the 3/4 inch schedule 30 pvc pipe to water our grow box. The holes are small, we ordered the number 57 drill bit from Amazon as our local stores don’t carry anything so small.
The holes are positioned to get a stream of water to squirt straight down into the bed and the other two at an angle towards the outside of the box. Our system will be drained in the winter as it turns cold. For all the piping that is below ground we elected to go with schedule 40 to help ensure we don’t have to dig up a broken pipe.
Currently we water by connecting a garden hose to the system. At some point we may go high tech and use a truly automated system.
Our grow boxes and in garden green house is beginning to come together. We now have two 18 inch wide by 30 feet long grow boxes built from treated 2 x 8 lumber in our garden. To those grow boxes we are adding the structure to allow us to grow vertically and support our in garden green house. The grow box construction is covered on page 78 of the MGC.
Before mixing and adding our growing medium, sawdust and sand for us, we added our pre-plant mix to the bottom of the grow box. Page 85 in the MGC book tells us to add one ounce per linear foot. So to this 30 foot grow box we measured out and added 30 ounces of pre-plant fertilizer. The grow box is now ready to be filled with a custom growing medium.
We utilized the free sawdust we were able to get locally to make our custom growing medium and sand. Following the MGC book, we mixed three parts sawdust to one part sand. This is mixed by volume and NOT by weight.
One 50 pound bag of all purpose sand filled a 5 gallon bucket so we used that as our measuring tool. After each bucketful of sawdust was added to our wheel barrow we added approximately 1/3 of a bag of sand. After the 15 gallons of saw dust and 5 gallons of sand were in the wheel barrow we mixed everything with a shovel before pouring it into the grow box. Each 10 foot section of our 30 foot grow boxes required 15 gallons of sand and 135 gallons of sand.
Once the grow box is full and level we have to add our pre-plant and weekly fertilizer to the medium and mix it in thoroughly. Page 87 in the MGC book calls for 1 ounce per linear foot of the pre-plant fertilizer mix and 1/2 ounce per linear foot of the weekly feed.
The fertilizer can be mixed in with a potatoe for or a shovel, but we have an attachment for our gas powered weed eater and will be using it.
These are a little late in coming, but both boxes are now full and there is more progress on the green house portion. Later today we will order the green house plastic to cover the structure
These 30 foot long and 18 inch wide boxes are being built for our fall crops. We will also be building an in garden green house over these boxes. This will allow us to extend our growing season by 12 weeks.
Once construction is complete they will be filled with a mix of sand and sawdust as our growing medium. As that growing medium contains no nutrients for the plants we will be providing all of the necessary nutrients via an inexpensive mix that is applied on a weekly basis.
The PVC you see next to the treated 2×8 serve a few purposes. They help hold the boxes level and in place once filled with our sawdust and sand growing medium. They also support the a-frames we will be making by heating and bending some half inch pvc. Once the mini a-frames are in place they can then be covered with green house plastic to protect our fall crops.
Next to the grow boxes you can see our sweet potatoes growing like mad.