Hybridizing of Tropical Waterlilies by Charles A. Winch
Paper presented during the Third International Waterlily Symposium held at Denver in August 1987
I wish to express sincere thanks to some very generous residents of Denver for making it possible for me to be here sharing with you my observations and experiences in the hybridizing of tropical waterlilies. Although we live on opposite sides of the Pacific Ocean, I am sure that we hold similar interests and hopes for the furthering of knowledge and enjoyment of water plants.
My experience with waterlilies goes back to 1928 when I obtained some Hardy plants. Then in 1938 this expanded to Tropical plants (Capensis). During 1953 I obtained 12 plants from the USA. Since 1978, when I retired as a wholesale supplier of goldfish and water plants, I have concentrated on tropical waterlilies as a retirement hobby.
By way of introduction, I would like to state that the views I express on the hybridizing of tropical waterlilies are not based on any scientific foundation but from my own personal observations and experiments over many years.
1. Selecting Parent Plants
I would suggest that you choose plants that have some of the characteristics that you wish to achieve such as: -
i. Growing habits
ii. Colour of leaves
iii. Colour of flower
iv. Shape of flower
v. Type and number of petals
As it takes a similar amount of time and effort to produce both good and mediocre plants, it is then obvious that the choice should be to produce the best that is possible. I have achieved good results using the following methods: -
a. Seed Parent
· As all tropical waterlilies do not set seed, it is important to select suitable parent plants that do so readily, and that give a fair number of large seeds.
· Most characteristics such as growth habits, shape of flower, number of petals (average 21), and leaves, appear to originate from seed parents.
b. Pollen Parent
· The pollen parent should provide ample amounts of pollen. Some plants have very little.
· Colour should be the next most important consideration. The pollen parents with Blue and Purple tones have the most dominating affect on seedlings, followed by Pink, Yellow, Afterglow shades, off White and, least of all, pure White.
2. Preparation of Planting Soil Mixture
This should be prepared about 2 to 3 months before planting time and consist of the following: -
· 12 parts light soil
· 4 parts coarse sand
· 1/3 part cow or poultry manure
· 1/12 part bone meal or blood and bone
The soil mixture should be stored in a covered position and kept slightly moist, not wet.
3. Method of Hybridizing
1) Select 2 (if possible) Pollen Parent buds that will open approximately 1 or 2 days before the opening of the selected Seed Parent.
2) Cover both the Pollen Parent and Seed Parent buds (with floating mesh or mosquito net), 2 or 3 days before they are due to open, to keep out the bees.
3) On the day the Seed Parent opens (at approximately 10am to 12 noon), when there is no dew on the flower (and hopefully no rain), use tweezers or forceps to extract several of the stamens from the Pollen Parent, and place them (anther down) into the nectar of the Seed Parent.
4) Re-cover the impregnated flower for at least 2 days.
5) The base of the flower should start to show some fullness in 7 to 10 days.
6) Place a stocking net bag over the flower with a float of polystyrene attached to it.
7) When ripe the seeds should float free in the bag, the stem having rotted away.
8) The seeds should then be placed in a container of clean water, and this should be changed a couple of times.
9) When the seeds sink to the bottom of the container wash them clean. The seed should now be ready to plant.
4. Seed Planting
1) For best results, the seeds should be planted within 3 or 4 days after collection from the water. I personally do not favour using dried seed.
2) If the seed cannot be planted, it should be kept wet in a sealed glass jar and placed in the food compartment of a refrigerator to prevent premature shooting.
3) When planting, the containers should be about 3 inches deep and filled with the prepared soil mixture to within ¼ inch from the top.
4) Add a thin layer of light coloured sand and gently spray with water until it becomes waterlogged.
5) The seeds should then be placed on top and spread evenly over the surface using a small brush.
6) The container should then be filled with dry coarse sand (covering the seed).
7) Gently place the container into a water tank, to a depth of 3 inches from the surface (bricks are useful for height adjustment).
8) The seeds should begin to show the first plant growth within 4 to 10 days and should be left from 4 to 12 weeks or when they have advanced to the stage of having developed 4 or 5 surface leaves, before replanting for either inside or outside locations.
9) Good results are obtained with average temperatures of approximately 70 degrees F (range 50 to 90 degrees).
10) Seedlings grown in hothouse conditions should not be placed outside until the daytime temperature reaches at least 70 degrees F. Even then, they should be covered with shade cloth for 2 weeks to help prevent burning from direct sunlight.
11) As a general rule, I do not keep fish or water snails in tanks with seedlings.
5. Possible Problems and Solutions
· Algae can be helped by: - the addition of pieces of charcoal, or small amounts of methylene blue solution poured on the worst affected area, or occasionally overflowing the tank.
· Blood worms and caddies fly often cut off leaves. Use a small amount of Dipterex.
· Aphids also attack surface leaves. Spray with Rogor 40 or other products used for aphids.
· Water snails may be disposed of by using Dipterex.
Good luck with your hybridizing efforts! I hope you will all experience the same enjoyment, pleasure and satisfaction that I have gained from growing and hybridizing tropical waterlilies.