Gladiolus tristis var concolor

Growing Hints

These are growing hints from 2 different people, both experienced growers of Bulbs:

1. I plant them in a mixture of Nursery potting soil & river sand – 2 thirds / to 1 third.   For both bulbs & seed.

Then around late June, I give them a liquid fertilizer ie 3:1:5 or even 6:1:5 (Multifeed – Flowergro 3:1:6).

Make sure that all bulbs & seed are kept moist throughout the growing season, then around mid-September I fertilise them again before they go dormant.

This ensures that they will again be good for the next season.

2. I found it best to rub the seeds together to remove the wings – they’re not needed for germination, and they tend to trap water and swell up thereby lifting the soil and causing dry patches. If only a few seeds and they’re spaced out on the medium, then don’t bother.

Seeds can be sown up to twice their diameter under the soil (if seed 1mm diameter then 2mm soil covering). It’s not exact but I wouldn’t go more than 5mm for the larger seeds.

Use clean sand minus any organic matter to cover the seeds. Organic matter is hydrophobic when dry and when eventually wet swells up and causes patches that dry out quicker.

Keep in the shade and constantly moist. Once the majority have germinated then gradually move into brighter light.

As a rule of thumb use at least an 18cm diameter pot for a standard 25 seeds.

Most Winter Rainfall Gladiolus will flower by the third season if grown generously.