Greenly Garden
Get the app
EN

When to plant hyacinths in Sumy: 20 September – 20 November

In Sumy, hyacinth: plant from 20 September to about 20 November.

Bulbs are best planted early in the window: late-planted bulbs may flower later or less well. Late planting works only while the soil can be dug. Mulch after planting.

The date is about two weeks before the average daily temperature here falls below 0 °C (ten years of weather): an estimate, not the day the ground freezes, and a cold spell can freeze it earlier. Sources: Iowa State University Extension, Wisconsin Horticulture Extension, UNH Extension, RHS, how the ground freezes (NRC Canada, CBD-26).

Hyacinth in Sumy: soil, season and weather

Nights then average below 0 °C in November–March; the coldest, January, averages -6.7 °C.

Planting20 September – 20 November
First autumn frost20 October
Coldest nightsJanuary, -6.7 °C
Soil back at 1 °C in spring27 February
Daylight12:23 on 20 September
Daylight at the winter solstice7:56

The same dates in Sumy hold for Garlic, Tulip, Daffodil and Crocus.

Hyacinth in Sumy: depth, winter cold, pests and pets

Plant hyacinths 10 cm deep, at least 7.5 cm apart (RHS). In the ground hyacinths are fully hardy, but in containers they can be frost tender in cold winters (RHS); here winter nights average below 0 °C, so wrap the pots or move them to a sheltered spot.

In Sumy the average daily temperature stays at 10 °C or lower for about 27 weeks a year (our estimate from ten years of monthly weather). For this bulb Wisconsin Horticulture Extension gives a cold period of 12–15 weeks at about 2–10 °C. The winter here gives that in the ground, so the bulbs need no pre-chilling.

Flowers get smaller in the years after planting: for full spikes, replace the bulbs or add a few new ones each autumn (RHS).

If squirrels are a problem, protect the bulbs with wire mesh (RHS). Hyacinths are toxic to dogs, cats and horses: intense vomiting and diarrhoea (ASPCA).

Sources: RHS, Wisconsin Horticulture Extension, ASPCA.

Hyacinth in nearby cities

Around Sumy, Oryol is 4 days earlier and Poltava 3 days later.

CityDistanceDateDifference
Konotop117 km21 September – 21 November1 day later
Kursk132 km21 September – 14 November1 day later
Kharkiv144 km21 September – 23 November1 day later
Poltava148 km23 September – 29 November3 days later
Stary Oskol217 km22 September – 13 November2 days later
Oryol245 km16 September – 10 November4 days earlier

Where to buy hyacinth for planting in Sumy

Planting stock goes into the ground from 20 September to about 20 November; buy it before that. Within 15 km of Sumy OpenStreetMap lists 2 garden centres, 1 farm-supply shop, 1 plant nursery, 7 markets and 2 farm shops (collected 7 October 2026).

Places: © OpenStreetMap contributors, ODbL.

Questions

When to plant hyacinths in Sumy?

In Sumy, hyacinth: plant from 20 September to about 20 November. Bulbs are best planted early in the window: late-planted bulbs may flower later or less well. Late planting works only while the soil can be dug. Mulch after planting.

When is the last spring frost in Sumy?

Last spring frost around 22 April, first autumn frost around 20 October.

Other crops in Sumy, with their dates