Forsythia in May: monthly care

Forsythia thrives in full sun or partial shade, though flowering is most prolific in a sunny position. It tolerates a wide range of soils—loam, clay, and chalky types all suit it well—provided drainage is reasonable. Before planting, dig a hole roughly twice the width of the root ball and fork over the base to break up compacted soil. If your ground is heavy clay, work in some grit or coarse organic matter to improve structure, though forsythia is generally unfussy. Plant bare-root specimens in March, April, September, or October when the soil is workable and not frozen or waterlogged. Container-grown plants can go in during the same months, ideally avoiding the height of summer. Set the shrub at the same depth it was growing in the pot or nursery—you should see a soil mark on the stem as a guide. Space plants 240 cm apart if you're creating a hedge or informal screen; forsythia will eventually reach 200–300 cm in both height and spread, so give it room. Backfill the hole with the excavated soil, firming gently with your heel to eliminate air pockets, then water thoroughly to settle the roots. Apply a 5–7 cm layer of well-rotted compost or bark mulch around the base, keeping it clear of the stems to prevent rot. Water again if the weather is dry over the following fortnight. Staking is rarely necessary unless the site is very exposed; forsythia establishes quickly and develops a sturdy framework on its own.

Forsythia has moderate water needs and tolerates short dry spells once established, but water during prolonged dry periods in spring and summer, especially in the first two years. A thorough soak every ten days is better than frequent shallow watering. Reduce watering in autumn and winter when the plant is dormant and rainfall usually suffices. Feed in March or April as growth resumes. Scatter a general-purpose granular fertiliser such as Growmore or blood, fish, and bone around the base at the rate recommended on the packet, then water in if rain isn't forecast. A second, lighter feed in late April can boost flowering the following year, but forsythia is not a heavy feeder and will perform adequately in average soil without much intervention. Refresh the mulch layer each spring to suppress weeds, conserve moisture, and gradually improve soil structure as it breaks down. Keep mulch a few centimetres away from the stems. Forsythia is generally pest- and disease-free. Occasionally you may see aphids on soft new growth in late spring; a strong jet of water usually dislodges them, or leave them for natural predators. Forsythia gall, caused by a bacterium, produces rough swellings on stems but is uncommon and rarely serious—prune out affected growth if it appears. This shrub is fully hardy across temperate Europe (zone 5a–8b) and needs no winter protection. Maintenance is genuinely low: an annual prune, a spring feed, and occasional watering in dry weather are all it asks.