There are a number of advantages to planting all female seed rather mixed seed or using clones:
- They do not have to be sexed so they can be started in place.
- Seedlings often have more vigor than clones and this makes dealing with them easier since there are no males to detect.
- When seeds produce male plants you are wasting time and energy on plants that will be tossed.
- You don’t have to overwinter plants to create mothers to cut for clones. Instead, you just start seeds in the spring.
- Seedlings do not carry nearly as many infections that clones do.
In addition, the technique can also be used:
- To make seeds from female only varieties.
- To create female x female hybrids without having to use a male.
To create female seed, a female plant is induced to produce male flowers.
The pollen only has female genetics, so all of the seed created using this pollen will be female. Most propagators use silver thiosulfate (STS), which is available on the internet in the form of two chemicals that are mixed together. I decided to try the STS as well as two other chemicals, available on the internet, 30ppm colloidal silver and also a spray product advertised to induce male flowers.
I started with four clones each of four varieties, Blue Dream, Candyland, Sour Diesel and Girl Scout Cookies. Each plant from each variety is being treated with one of the three chemicals or being used as a control. Each chemical is being tested on each of the varieties.
All the plants were placed in 6” containers holding coir and peat based planning mix. They are all irrigated using the wick system. The 3/8” nylon wick draws water to the bottom of each container from the reservoir below using capillary action, which also draws water up the soil, keeping it moist.
After planting, the plants were placed in a greenhouse lit by natural light about 13 hours a day. Most of the light is indirect but the plants do receive about four hours of direct sun each day. In addition, a 1000-watt stationary HPS lamp is placed about three feet over the plants. It is on seven hours a day, from 10am-5pm. During the three to seven days from transplanting a fluorescent light providing dim light turned on four
times each night for half an hour to break the dark cycle and keep the plants growing vegetatively.
One day after the supplemental night lighting was eliminated, each experimental plant was marked and sprayed. According to instructions for the colloidal silver and the commercial product, the plants should be sprayed daily for the next for three weeks. The sodium thiosulfate required spraying just once.
If the experiment is successful, within a month the plants should be growing male flowers and producing viable pollen. Within a month, if the experiment is successful the plants will be growing male flowers.
- Photo 1 – The plants are marked by variety and were placed in rows according to their treatment schedule.
- Photo 2 – These plants of four varieties were all treated with the commercial feminizing spray. Each treatment chemical was assigned a color for easy identification.
- Photo 3 – Spraying the small bottle of commercial spray on one group of plants.
- Photo 4- The clones had just been planted a week before treatment started so they are small. Nevertheless, they are excellent models to work with because they are easy to carry and move, so moving them to an isolated spray area is not much of a chore.
- Photo 5 – Close-up of stem shows that the plants are still in vegetative stage. The light period had just been shortened two days before first spray.
TIP OF THE MONTH
As you harvest and trim your plants save all of the clean green leaf. It can be used for cooking, salves and tinctures or to make concentrates. If you take an ice cooler packed with ice cubes covered with paper or cloth to the field, place cut leaves in the cooler to keep them fresh. Rinse them in cool, not cold water, so the glands remain pliable rather than becoming brittle. Use a wheat grass juicer for fresh juice or freeze them for later processing. Use the juice can be used fresh or freeze it in ice cube trays for individual servings.