Micropropagated plants of common ash and wild cherry were inoculated with arbuscular mycorrhizal fungi during a 20-day weaning period, after which they were transferred to two different substrata supplemented with slow-release fertilizer. After a 13-week growth period, the stem height and diameter of the ash plants which had been inoculated with Glomus intraradices were three times greater than those of uninoculated control plants. Increasing the peat content of the substratum improved growth of ash. Four weeks after being transferred to pots, shoots of wild cherry inoculated with G. intraradices or G. deserticola were taller and stems thicker than those of control plants, whereas those inoculated with Gigaspora rosea had shorter shoots and thinner stems than the controls. These beneficial effects of fungal inoculation on plant development disappeared after 13 weeks. Increasing the peat content, but not the level of fertiliser of the substratum, improved growth of both inoculated and uninoculated wild cherry.