When to Plant Lilies in USDA Zone 4a
Your June planting checklist for Zone 4a
We've pulled the most time-sensitive tasks for Zone 4a this June and put them front and centre. Tackle them in order.
Lilies (Lilium spp.) are among the most impressive summer-blooming bulbs, delivering bold, upward- or outward-facing trumpet blooms on tall stems from June through August. Asiatic hybrids are the most cold-hardy, earliest to bloom, and easiest to grow; Oriental hybrids bloom later with intensely fragrant, larger flowers. Orienpet (OT) hybrids combine the hardiness of Asiatics with the fragrance and size of Orientals. True lilies (not to be confused with daylilies, which are Hemerocallis) form scaly bulbs that persist and multiply underground, returning reliably each year with increasingly large clumps.
In Zone 4a, the average last spring frost is around May 6 and the first fall frost is around September 28, giving you a growing season of approximately 145 days.
Lilies Planting Timeline — Zone 4a
Where Is USDA Zone 4a?
The map below highlights the states that contain Zone 4a. Click any state to see the Lilies planting schedule for that location.
Lilies Planting Calendar — Zone 4a
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 20 | May 20 – Jun 3 |
| Bloom | August 12 | Aug 12 – Oct 14 |
Plant 5" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Free Zone 4a Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4a with start dates, transplant windows, and harvest times.
Growing Conditions
Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
Days to Maturity
70–120 days
Soil pH
6 – 6.5
Zone Temperature Range
-30°F to -25°F average annual minimum
Growing Season
145 days (Zone 4a average)
Planting Specifications
| Planting Depth | 5 inches |
| Plant Spacing | 12 inches apart |
| Row Spacing | 18 inches between rows |
Succession Planting Lilies in Zone 4a
Sow every 8 weeks for continuous harvest throughout the season.
Growing Tips for Lilies in Zone 4a
Zone 4a has a short growing season (~145 days). Start Lilies indoors early and use season-extension techniques like row covers and cold frames.
Plant bulbs in fall (preferred, September–October) or spring, setting them 3 times their diameter deep (typically 4–6 inches) with the pointed end up. Lilies need excellent drainage — they will rot in wet or heavy clay soils. Site with full sun on stems and blooms but cool, shaded soil at the base (ground cover or shallow-rooted annuals at their feet is ideal). Remove spent blooms but leave stems and foliage until they yellow naturally, as the bulb needs the foliage to photosynthesize and rebuild energy stores. Red lily beetle is a serious pest in the Northeast and Pacific Northwest; inspect plants regularly and hand-pick adults and larvae. Never plant Oriental or Asiatic lilies near cats — all Lilium species are highly toxic to cats. Year 2+ bulbs produce the most stems and largest blooms.
Companion Planting
Good Companions
The Gardener's Encyclopedia to Companion Planting
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
- Full seed-starting + planting schedule with timing and spacing
- Bonus: square-foot gardening guide + printable seasonal planners
Saving Lilies Seeds
Recommended for Your Garden
Full-spectrum LED lights for starting seeds indoors when daylight is limited.
Warm soil for faster germination of heat-loving crops like tomatoes and peppers.
Protect plants from frost, wind, and pests while letting light and water through.
Related Plants
Lilies in Other Zones
Lilies by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Lilies in Zone 4a?
In Zone 4a, plan your Lilies planting around the average last frost date of May 6. Transplant seedlings around May 20.
Can Lilies grow in Zone 4a?
Yes, Lilies can grow well in Zone 4a, hardy in USDA zones 3a through 9a. Zone 4a has a growing season of approximately 145 days, which is sufficient for Lilies (70-120 days to maturity).
When can I harvest Lilies in Zone 4a?
In Zone 4a, expect to harvest Lilies from August 12 – October 14. Lilies takes 70-120 days from planting to harvest.
What is the last frost date for Zone 4a?
The average last spring frost in Zone 4a is around May 6, and the first fall frost is around September 28. This gives a growing season of approximately 145 days. These are 50% probability dates — actual frost dates vary year to year.
What should I plant next to Lilies?
Good companion plants for Lilies include Hostas, Daylily, Phlox, Black Eyed Susan. These companions can help with pest control, pollination, and nutrient sharing.
Your Zone 4a Garden Planner — Free
A 22-page printable planner tailored to Zone 4a. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.