Chapter 20

Hybridizing Gladiolus.

The gladiolus, owing to the large size of the blooms and its open character, is one of the easiest plants to pollinate artificially. Healthy vigorous plants should be selected for seed bearers, and the bloom spike supported with a firm stake. The blooms should be visited in early morning as they open, and the anthers removed before they have shed pollen, with the fingers, or better with slender forceps, taking care not to injure the style or the three-parted stigma, which will be ready to receive pollen about midday in bright weather or late in the afternoon, or even next day if cloudy or dull.

The blooms should, immediately after the anthers have been removed, be covered with thin cheesecloth, or "bobinet," firmly tied or pinned in such a manner as effectually to keep out bees and visiting insects. Ordinary mosquito netting will not serve after it has been wet with dew or rain, as the mesh becomes so loose that energetic little pollen carrying bees force their way through, often entirely spoiling results. The pollen-bearing blooms should be carefully selected to open the same day and should be as well protected with muslin or fine netting as possible to prevent robbery of pollen.

About noon, when the anthers are covered with dry-dust-like pollen they can be pinched out with forceps and carried to the seed-bearing spikes in a covered dish to protect from wind. The anthers may be taken separately in the fingers, or with forceps, and lightly brushed over the stigmas, which should be erect and open if they have reached the receptive stage. One anther will usually suffice for a seed bloom if pollen is abundant, but in some of the lighter-colored varieties it is scantily produced and several may be needed. Occasionally the anther valves do not open freely enough to permit the escape of pollen, which may then be taken out with a narrow-bladed penknife, or better with a little instrument made of a flattened pin fixed in a wooden handle.

The pollinated blooms should immediately be covered with the netting, which should remain until they fade. If conveniences are at hand the work may be rapidly accomplished--several hundred pollinations being made in a single day by an active worker. Pollen can also be used from cut blooms, the spikes being kept in water in a light room, free from flies or bees, but it gradually loses power when the upper blooms open under such artificial conditions. If the work is carefully done the resulting seeds will produce hybrids or cross breeds as the case may be, and it is always possible that the ideal sought for may appear among the number. Pollen may be kept a week or more by drying in the shade and wrapping in paraffin paper, but is far less reliable than if applied fresh from the anthers.

The blooms of large garden varieties are rarely self-pollinated, even if left uncovered, but the chances of fertilization with inferior kinds, generally the most abundant pollen producers, are so great that it is well to protect all seed-bearing blooms from insect interference. If the work is to be done on a large scale sleeves of netting or muslin large enough to enclose the entire spike will be found serviceable. The ends may be drawn together by cords looped through the fabric, effectually barring out the meddling bees. If a greenhouse structure or even a well lighted room is available, the plants may be grown in large boxes or pots and taken inside when blooming. This is especially desirable in the case of rare species and varieties, as there is no interference from stormy weather. Every bloom can be pollinated and practically every grain of pollen utilized under these secure conditions.