I harvested in mid July some columbine seeds (unknown Aquilegia cultivar). Can I plant outside now? Do I need to start indoors? Or wait?
A great book resource used to find this answer was Seeds: The Ultimate Guide to Growing Successfully from Seed by Jekka McVicar. In the book, McVicar recommends “sowing fresh seeds in early summer into pots or modules using standard soil-less seed compost (substrate), either a peat free proprietary blend or composted fine propagating bark. Cover with perlite or vermiculite. Place under protection at 50F (10C)” If the seeds are old (viable for 5 years), “sow seed in autumn into pots. Use standard loam-based seed compost (substrate) mixed with coarse horticultural sand. Mix to a ratio of 1 part compost + 1 part sand. Cover lightly with compost and place outside, exposed to all the weathers. Germination takes place the following spring but can be erratic. May flower in its first or second season.” (p.145)