N A P S Northern Section

                                        SEED PRODUCTION

A natural progression from getting and growing a few primulas or auriculas is producing your own plants from seed, this can be very rewarding and can also provide you with extra plants at very little or no cost. While species primulas in the main come true from seed (there are exceptions) auriculas do not come true from seed and to keep a selected variety going vegetative propagation has to be used, this means taking and growing on the offsets that your plant produces, this is fine to keep and get more of a specific plant for your own use and to pass on to friends and colleagues however to produce fine new varieties you have to resort to seed to achieve this. To any growers who have not done this before it may seem a daunting task that many might shy away from happy to let others produce new varieties then swap or buy them. Whilst it is true that Genetics can be a complex and daunting subject you will be able to achieve good results from just a few simple basics then if you chose to with some experience under your belt you can take it further if you wish.

          fig 1, Pin        photo by M Martin

fig 2, Thrum

The procedure is basically the same for seed production of most if not all plants, here I will deal specifically with auriculas. Ideally a male and female plant are used for seed production in general or as they are known to plant breeders a Pin and a Thrum, the Pin being the male and the Thrum the female (see fig 1 & fig 2). However only Thrums are kept by most Florists from seedlings raised and whilst you could use a seedling Pin to cross pollinate you would not find a fine named auricula that was a Pin that you could use. A plant is classed as a Pin when the stigma protrudes through the stamens and a Thrum when the stigma sits below the stamens, the stamens being the filaments that are arranged around the tube of the flower and carry the pollen that when ripe is transferred to the stigma, this can be done by the wind, bees or man and if done at a time when the pollen is ripe and the stigma receptive seed will usually follow a few months later. A Thrum plant crossed with a different variety Thrum plant is the preferred method used by most "Florists" or breeders of auriculas, and usually auriculas are crossed like with like, i.e. a Gold Centre Alpine with a Gold Centre Alpine or a Green Edged with a Green Edged and a Self with a Self. It is no more difficult doing a Thrum to Thrum cross than it is with a Thrum to Pin, it simply means you have to carefully tear or cut some of the flower away to reveal the Stigma or Pin on the plant you have chosen to be the seed parent in order to reveal the stigma see fig 3 & fig 4. Seed parents and pollen parents are chosen by the hybridist with a view to producing new plants which are an improvement on the parent plants, the aim is to produce plants containing the better attributes of both parents. One plant for instance may be of fine form but a better or stronger colour may be desirable so chose a partner plant that has better or stronger colour and hopefully one or more of the seedlings will have the fine form of one parent and the better colour of the other parent. It has to be said that most seedlings produced are not as good as the parents and only those with better form than the parents or new colour breaks should be kept with a view to exhibiting and if good enough eventually naming.

fig 3,     Tearing the flower to reveal the pin

fig 4,     pin ready to receive pollen

It is said that the best time to make crosses is around midday on a bright warm sunny day when the pin or stigma becomes sticky or receptive, also make sure the pollen to be used is ripe, a good golden colour and fluffy if it isn't ripe the pollen grains will appear smooth and hard, if the pollen is a dull colour with a slight grey appearance its past its best and probably no good. Some use a fine artists paint brush to transfer pollen from the stamens to the stigma with a light dabbing action so if more than one cross is being made the brush should be carefully cleaned after each cross or contamination will occur. Another and safer way to put the pollen onto the stigma is to remove a stamen at its base from the plant you are using as pollen parent with a pair of tweezers and then gently rub or brush the pollen onto the stigma, fig 5, use a magnifying glass if necessary to check the pollen is sticking to the Stigma, this can be repeated on several flowers if desired by using a fresh stamen for each stigma. Another way is to remove a whole pip or flower that you intend to use as the pollen parent then carefully trim the petal away with a pair of small scissors to leave just the tube of the flower containing the stamens then holding the base of the tube between finger and thumb you can then touch the stamens to the awaiting stigma or stigmas on the seed parent plant, make a note the cross on a label and put it into the pot with the plant you have pollinated.

A greenhouse or cold frame is the ideal home for your auriculas prior to and after pollination and the plants should be kept dry shaded and cool where possible and well ventilated, fine mesh over open doors and windows will keep a good supply of air flowing over the plants but more importantly keep bees and other bugs from contaminating your cross with pollen from other plants. Make sure the plants don't dry out as this could stress the plant and prevent seed setting then all being well you will see the seed pods begin to swell and can look forward to the fruits of your labour with a crop of seed. Once the pods swell to their maximum keep an eye on them and the green cover over the seed pod will eventually begin to dry and change colour, it changes gradually to the colour of straw or light brown and usually cracks across the cover fig 6. Carefully remove the seed pods and by gently squeezing the pods over a container or sheet of paper the seeds of a light to dark golden brown will tumble out. Seed from each cross should be put into small paper or glassine seed envelopes (never use polythene bags) and clearly marked with the variety, parent plants crossed and the year. The best way then to store and save your seed to keep it fresh is to put the seed envelopes into an airtight container in the refrigerator, some sow the seed immediately but others prefer to save the seed of auriculas and sow it in January and February the following year, spare seed can be saved for a number of years as described and shared with friends, colleagues, or sent to society seed exchanges where it is very much appreciated by all who use the seed exchanges.

fig 5, pollen on a stigma

fig 6, seed pods ready for harvesting, photo R Taylor

Members ! please remember our seed exchange if you have spare seed, and good luck.

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