Updated 11 September 2026
When will Slippery Jack appear in Jönköping?
This week’s slippery jack forecast for Jönköping, Sweden reads 56% and looking good. The 14-day outlook decides whether to go now or wait, so check https://shroomcast.net/forecast/slippery-jack-forecast-for-jonkoping-sweden/ before you set out
It fruits after warm late-summer and autumn rain, typically when day temperatures sit around 10 to 20C and the ground stays damp. A good soaking followed by mild nights usually brings flushes within a week or two.
In the same pine woods and season look for other Suillus such as larch bolete and weeping bolete, plus saffron milkcaps and the occasional bay bolete or porcini on richer patches. False chanterelles and various brittlegills often share the same acidic ground.
Scan the ground near any pine, especially along sandy tracks and clearings where they often appear in groups. Pick young firm caps, since older ones go soft and waterlogged, and carry them separately because the slimy cap coats everything.
Other Suillus boletes such as the larch bolete (Suillus grevillei) and weeping bolete, all of which are also edible, so there are no dangerous poisonous lookalikes. The slimy brown cap, yellow pores and ringed stem set it apart from any toxic gilled mushroom.
Jönköping County sits on the southern Swedish highland (Sydsvenska höglandet), a rolling upland of forest, glacial moraine and countless lakes and peat bogs. Its eastern edge meets the great Lake Vättern, with the city of Jönköping at the lake’s southern tip. The county is dominated by Småland’s coniferous forest, mostly Norway spruce and Scots pine mixed with birch, with patches of beech and oak in the south. Chanterelles and porcini thrive in the mossy spruce stands, along forest edges and on the blueberry-covered slopes.
Being raised highland, the region is cooler and noticeably wetter than the surrounding lowlands, catching heavy rainfall that keeps the forest floor damp well into autumn. These moist, mild conditions make it reliable mushroom country from late summer onward. This is classic Småland foraging territory: expect generous chanterelles, funnel chanterelles and Karl Johan (porcini) in the spruce woods, with vast tracts of open access forest under the right to roam (allemansrätten). The season builds from August and often runs strong through October.
FAQ
Does ShroomCast tell me if a mushroom is safe to eat or identify it for me?
No. ShroomCast only forecasts timing, so it tells you when slippery jack are likely to be fruiting in Jönköping, Sweden. It does not identify mushrooms, and it cannot tell you whether anything you pick is safe to eat. Always confirm your own identification from a reliable source before eating anything.
How does the live slippery jack forecast for Jönköping, Sweden work?
We take the usual slippery jack season for Jönköping, Sweden (August to November) and weigh it against the weather right now and over the last few days. That gives you one live number, today 56% and looking good, plus a 14-day outlook and a normal-year line to compare against.
When is slippery jack season in Jönköping, Sweden?
In Jönköping, Sweden, slippery jack season usually runs August to November. The exact start shifts year to year with rain and temperature, so some years they show up early and some years late. Right now (September) the live forecast for Jönköping, Sweden reads 56% and conditions are looking good.
Where do slippery jack grow in Jönköping, Sweden?
Grows in conifer woods, almost always with pine, on sandy or poor soil and often along forest tracks and clearings. Common in young plantations and appears in groups. They tend to come back to the same kinds of ground year after year, so once you find good cover it is worth checking again. ShroomCast does not share exact spots; it tells you the timing for Jönköping, Sweden so you know when it is worth heading out.
How do I know slippery jack season has started in Jönköping, Sweden?
Season usually kicks off after a warm spell followed by steady rain, with the first flushes appearing somewhere in the August to November window. The clearest sign is the live forecast lifting off zero into ‘just starting’ or ‘building’. For Jönköping, Sweden it currently sits at 56% and is looking good.
See the live regional forecast in the ShroomCast app.
This page shows today. The app gives you the full 14-day outlook for your area and all 14 species, so you can pick the right day before you drive out.
Scale: 0-20% very low · 20-40% low · 40-60% moderate · 60-80% high · 80-100% excellent. ShroomCast forecasts fruiting probability from weather, soil, forests and years of observations – a guide, not a guarantee of finds.
ShroomCast forecasts the region and the time of year. It cannot identify mushrooms for you, so confirm any species with a reliable source before eating it.