Snow on purple coneflower seed heads left standing in a winter garden

Free days and after-dark: the cheapest way into a garden this fall, and what the pros leave standing

Pests and disease
September 07, 2026

A trip to Denver Botanic Gardens does not have to cost anything.

Neither does the biggest lesson it can teach your own fall cleanup: what to leave alone, and what actually has to go.

A free ticket exists, but it sells out

Denver Botanic Gardens runs Free Days throughout the year, funded by the Scientific and Cultural Facilities District. The next one at both York Street and Chatfield Farms lands on Friday, Nov. 27, the day after Thanksgiving.

The Aug. 25 York Street date already sold out. If you want Nov. 27, get a ticket now rather than counting on walking up. Free Days tickets release three months out, on the 1st of each month, and cover regular hours only, not the ticketed events below.

Denver Botanic Gardens DSC01022 A free ticket still needs a reservation once the popular dates are gone.

After dark costs more, and needs a plan

Two nighttime events this fall are not free, and not walk-up either. Glow at the Gardens runs Oct. 15-18 and Oct. 21-24, 5:30 to 9 p.m. Ghosts in the Gardens runs Oct. 9-10, Oct. 20, and Oct. 28-31, at various times.

Both require a timed ticket bought online in advance, since tickets are not available onsite and Glow especially sells out weeks ahead. Treat the date picker like a reservation, not a suggestion.

What the pros leave standing all winter

Here is the part worth stealing for your yard: most garden invertebrates do not go anywhere for winter. According to the Xerces Society, they overwinter right where they lived all summer, just quieter and better hidden:

  • In a couple inches of leaf litter.
  • Inside hollow plant stems.
  • In brush piles and dead wood.
  • In the top few inches of soil.

That litter is doing real work. Small carpenter bees nest in dead raspberry canes and old wildflower stems, and according to the Xerces Society, roughly 30 percent of native bees are tunnel-nesters needing those same hollow stems or dead wood to survive. Mated bumble bee queens burrow an inch or two into bare ground and rely on a thick layer of leaves for insulation.

Rake all of that to the curb in October and you are not tidying up, you are evicting next year's pollinators.

The Xerces Society's advice is blunt: leave it standing through winter. If you must clean up, wait until late spring so you do not undo the shelter you built. Diseased plant material and pest-harboring vines are the one exception, since they carry problems forward instead of shelter, so those still come out now.

Denver Botanic Gardens 12 A messy bed in October is a nursery, not neglect.

Bottom line

  • Free Days at Denver Botanic Gardens run on a rolling three-month release; the next one is Nov. 27, per the Gardens' own Free Days page.
  • Glow and Ghosts in the Gardens both need a timed ticket bought ahead, per the Gardens' fall events page.
  • Most garden invertebrates overwinter in leaf litter, hollow stems, and brush piles right where they lived all summer, per the Xerces Society.
  • Diseased plants and pest-harboring vines still need to come out now; healthy stems and litter can wait until spring.

Your zone

  • Zone 3-4: Frost can be close by late October, so grab an after-dark ticket or plan around the Nov. 27 free day soon. Stems and leaves already down in your beds are sheltering insects, so leave them through the freeze and clean up in spring.
  • Zone 5-6: This is Denver's own band. Free Days, Glow, and Ghosts all run on the schedule above, so book ahead and treat Nov. 27 as the budget option.
  • Zone 7-8: Your fall runway is longer, so check whether your local public garden runs a comparable event: [VERIFY: local public garden free-day and after-dark event calendar]. Either way, the leave-it-standing rule applies wherever you garden.
  • Zone 9-10: Same on the event calendar: [VERIFY: local public garden free-day and after-dark event calendar]. Overwintering habitat still matters, since plenty of native bees and butterflies are tunnel-nesters or leaf-litter dwellers no matter how mild the winter is.
  • Zone 11+: Same on the event calendar: [VERIFY: local public garden free-day and after-dark event calendar]. No hard frost means no forced cleanup deadline, so "wait until late spring" is easy to keep.

Sources

helpzone 3-4zone 5-6zone 7-8zone 9-10zone 11+
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Garden Hero

We have killed more plants than you have grown. Rooted is what we learned, sourced to the extension office and written by your zone.

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