Updated 13 September 2026
When is the best time to find Slippery Jack in Hautes-Alpes?
Mushroom season in Hautes-Alpes, France is building right now, with slippery jack sitting at 38% today. The typical season runs August to November, and we’re in September now
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.
It has a distinct membranous ring or partial veil remnant on the stem, an unusual feature among the slippery-capped Suillus boletes.
Always peel off the slimy cap skin and remove the spongy pore layer first, as both can upset the stomach. Slice and fry in butter for a soft side dish, add to risotto or stews where the texture suits, or dry the cleaned pieces and grind into a savoury mushroom powder for stocks and sauces.
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.
Hautes-Alpes is one of France’s highest and least-peopled départements, deep in the southern Alps. Glaciated peaks of the Écrins rise past 4,000 metres, while the Durance carves broad valleys and feeds the vast Serre-Ponçon reservoir. Between summits stretch high pastures and the valleys of Queyras, Dévoluy and Champsaur. Conifers rule these slopes: larch woods, a signature of the southern Alps, mix with Scots and mountain pine, Norway spruce and silver fir, giving way to beech on lower, shadier ground. The open, sunlit larch stands and their mycorrhizal roots make especially rich, well-drained ground for boletes and other symbiotic fungi.
Sheltered from Atlantic rain, Hautes-Alpes ranks among the sunniest and driest French départements, with cold winters and warm summers. Precipitation is modest, so fungi depend on late-summer and autumn thunderstorms for moisture. The season runs mainly August to October, starting high and dropping with the cooling weeks. Foraging here means climbing after the storms, hunting the damper larch and spruce stands and stream margins where moisture lingers. Cèpes and girolles reward the walk, alongside larch boletes tied to the mélèze, other Suillus under the pines, and saffron milk caps. The dry ground concentrates finds into the greenest pockets.
FAQ
How does the live slippery jack forecast for Hautes-Alpes, France work?
We take the usual slippery jack season for Hautes-Alpes, France (August to November) and weigh it against the weather right now and over the last few days. That gives you one live number, today 38% and building, plus a 14-day outlook and a normal-year line to compare against.
When is slippery jack season in Hautes-Alpes, France?
In Hautes-Alpes, France, 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 Hautes-Alpes, France reads 38% and conditions are building.
Where do slippery jack grow in Hautes-Alpes, France?
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 Hautes-Alpes, France so you know when it is worth heading out.
How do I know slippery jack season has started in Hautes-Alpes, France?
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 Hautes-Alpes, France it currently sits at 38% and is building.
Are slippery jack out near me right now in Hautes-Alpes, France?
Today the slippery jack forecast for Hautes-Alpes, France is 38% and conditions are building. That is a live read for the region this September, and it shifts with the weather rather than following a fixed calendar. It tells you if it is worth heading out in Hautes-Alpes, France right now.
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.