Spring is a time of renewal and winter is a good time to prepare for spring. About this time of year, anyone who gardens or has a greenhouse or small farm gets their seed catalogues in the mail. These are great as they present a wide array of vegetables for the planning and selecting what to grow. So, what could possibly be better than getting your favorite seed catalogues? Hint: This week, we were thrilled to see the delivery of a bale of seed starter soil mix and seed trays as it signifies a new beginning.
By purchasing only seeds from a seed catalog, we select varieties that probably weren’t bred for the set of conditions that work best for us. As growers, an additional goal is to develop varieties and diversities that are specifically adapted to our unique conditions of agriculture here in Potter County, Pennsylvania . We look forward to spring with great anticipation with the prospect of growing out our own botanical seed. By doing this over time, we hope to develop unique garlic and potatoes adapted to our environment and set of growing conditions. And also, hopefully we can select the traits of taste and texture that are desirable to us and our customers.
Learning is the process of gathering knowledge and then applying it. In doing this why not start by learning from the best? With that in mind, we are following the lead of a internationally recognized potato and tomato breeder Tom Wagner. Luckily for us, he shares his knowledge and encourages others to do this kind of thing.
Below is Tom Wagner’s Method for growing True Potato Seed (TPS):
True Potato Seed (TPS) germinates from five days to as long as several weeks with the majority emerging in 7 to 12 days. TPS is sporadic in the way it germinates and some seed will last in the soil for a year. New seed will germinate slower than seed two or fifty years old. So the younger the seed the harder it is to break dormancy.
The soil temperature is a factor: 72 F is the best temp, with 66F to 78F acceptable. Even temps day and night is required…a hot day in the greenhouse followed by a night in the 40’s would be too much of an extreme
Tom Wagner sows a lot of TPS and starts with a 72 cell insert put into one of those 11 by 21 inch trays. He uses a sterile peat lite seed starter type media. Sunshine #4 Natural & Organic is recommended where high air capacity and fast drainage are needed: during winter months, with water or salt sensitive crops, or where frequent leaching is required.
- Sunshine Natural & Organic Aggregate Plus 3.8 cubic feet bale
- Weight: 82.0 lbs.
- Package Dimensions: 26.0L x 16.0W x 14.0H
Sowing the seeds Level the media off to the top of the insert. Compress an indentation with your fingers pressing down the media down a fraction of an inch 1/8 inch/ 3mm. Then sow one to 10 seeds per cube depending on your objectives and rarity of the seed. Cover the seed with just a smattering of soil…1/8 inch/3mm or less then press it down again with your fingers. This firming down of the soil media allows one to water without flooding the media and floating off the media and seed. Water the flat in with 120 F/ 49C water to hasten the swelling of the seed coat. The competition helps germinate slow germinators and the first to germinate helps the stragglers stretch to keep up. It is highly significant if you can give the seedlings intense light just as soon as they emerge in order to keep them stocky. Give direct sunlight or have florescent grow lights within inches/50mm of the soil. 12 to 24 hours a day of light is critical. 8 hours or less of light makes the seedlings spindly. Do not cover the flat with plastic or a lid as damping off, fungus etc is a common killer of potato seedlings. The soil should be moist but not wet and needs to dry out a bit between waterings. If you have a grow mat for germinating TPS that is perfect for winter time, late Spring when the days are warm wouldn’t need the grow mats. As the plants grow they can tolerate the cooler nights but not below 55 to 65F/12 to 18C ideally. Try not to exceed 80F/27C degree days in the greenhouse. As seedlings grow their 2nd true leaves and are about 2 inches/50mm tall carefully transplant back into 72 cell trays one seedling per cell. The seedlings will not have many roots and breaking the root (s) happens often. Transplant those whose roots are totally broken often re-root. It is important to transplant into small containers because you don’t want wet soil and a root ball must start within the confines of the one inch/25mm square cell. Be sure to bury the cotyledon and maybe one of the true leaves leaving just a bit of plant above the soil to finish growing taller. The first transplanting occurs about three weeks after seeding. Mix a stronger soil media by starting with the above Sunshine media and mix in worm castings, dolomite lime, compost, composted manure, bone meal, alfalfa meal, kelp meal, blood meal, greensand, rock phosphate, wood ashes, cottonseed meal, etc. Not too much but just enough to give the soil media some oomph. Another two to four weeks later the seedlings should be about three inches/75mm high and if the flats are taken outside on some mild days to get acclimated to the sun for a few hours a day. This prevents transplant shock when you take them to the field or garden. Transplant to the garden in a shallow furrow and cover up another leaf or three so that very little of the plant is showing above the soil line. Water in and wait a week or two before bringing a bit more soil up around the stem. Space seedlings about 10 to 12 inches/ 250mm to 300mm apart within the row and my rows are at least three feet/900mm apart. At 4 ft/1200mm you can walk between the rows and use a tiller close to either side of the row to work the soil. As a few more weeks go by, more soil is hilled up around the seedlings so that about four inches/100mm of soil is above the original root ball. The potato needs to have these frequent hillings to allow it to root in and within the dormant buds in the apex of the leaf stems. Either more above ground stems will emerge out of the soil or if no extra stems, the plant will shoot stolons out from those buried leaf attachments to form tubers. By bringing more soil up around the seedlings one is eliminating weeds from taking over. If you till between the rows just before canopy closure weed pressure is reduced to a minimum.
When to sow 5 to 8 weeks prior to your last frost date this information can be acquired from weather bureaus and perhaps online. For instance Canada would be mid May or later. It is OK to start your sowing later or on weekly intervals all winter and Spring but the idea of putting the seedlings out after all danger of frost is past is to mimic tuber plantings. Tubers are usually planted in the ground 4 to 5 weeks before the last frost date. If one starts the seedlings too early like in February the potato seedlings grow mature and reach a senescent state when the potato leaves start to turn yellowing and stop growing thus tuberisation has occurred. Once the seedlings start their first little tuber there is but a short window to get them into the field. If the tubers grow for a while the seedling will die down and will not recover from the transplanting to the field. Only the late maturing ones will survive and grow into a full size vine. The ones that die down are the early maturing clones. The best time to transplant is when just a few of the seedling begin a tuber and you’ll know this when you transplant. Harvesting tuber hills can happen over a range of a month or more. Dig those that die down early and harvest the late vines before frost comes.
Transplants TPS growout effort is poorly understood by new readers. A TPS seedling is near worthless if transplanted with the cotyledon above the soil line….no tubers!
Seed pods Potato berries need to be on the potato vine for about 6 to 8 weeks after flowering. The berries don’t have a special colour when ripe even when soft they may still be greenish although a bit yellowish. Leave them alone as long as possible on the vine but if they fall off naturally gather them and allow them to ‘ripen’ a few more weeks indoors.
Organic soil prep Within the row at the time I place the tubers or TPS transplants, use a combination of minerals along with some kind of NPK feeding. This will mean kelp meal, alfalfa meal, cottonseed meal, dolomite lime, bone meal, rock phosphate, blood meal, humic shale, microbials, compost, pelleted chicken, etc.
Produce first year seedling tubers
Produce potato plants the following year
Produce viable pollen
Tom Wagner aka Tater Mater demonstrating TPS transplanting. Thank you for being a great teacher!
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