Season shown in 3 of Ohio's 88 counties. Explore Ohio
No result yet (7)
Recorded, too few records for a result (53)
Recorded, season not shown (25)
Season shown (3)
Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files, 1:500,000. Show as a table
Counties as a table
eastern poison ivy by Ohio county: records and mapped range
County
Records
Adams County
Recorded, too few records for a result
Allen County
26 · Recorded, season not shown
Ashland County
Recorded, too few records for a result
Ashtabula County
20 · Season shown
Athens County
383 · Recorded, season not shown
Auglaize County
Recorded, too few records for a result
Belmont County
Recorded, too few records for a result
Brown County
Recorded, too few records for a result
Butler County
102 · Season shown
Carroll County
Recorded, too few records for a result
Champaign County
Recorded, too few records for a result
Clark County
Recorded, too few records for a result
Clermont County
61 · Recorded, season not shown
Clinton County
Recorded, too few records for a result
Columbiana County
Recorded, too few records for a result
Coshocton County
Recorded, too few records for a result
Crawford County
Recorded, too few records for a result
Cuyahoga County
238 · Recorded, season not shown
Darke County
Recorded, too few records for a result
Defiance County
Recorded, too few records for a result
Delaware County
97 · Recorded, season not shown
Erie County
26 · Recorded, season not shown
Fairfield County
20 · Recorded, season not shown
Fayette County
Recorded, too few records for a result
Franklin County
230 · Recorded, season not shown
Fulton County
No qualifying records yet
Gallia County
Recorded, too few records for a result
Geauga County
42 · Recorded, season not shown
Greene County
42 · Recorded, season not shown
Guernsey County
Recorded, too few records for a result
Hamilton County
245 · Season shown
Hancock County
Recorded, too few records for a result
Hardin County
Recorded, too few records for a result
Harrison County
Recorded, too few records for a result
Henry County
No qualifying records yet
Highland County
Recorded, too few records for a result
Hocking County
24 · Recorded, season not shown
Holmes County
Recorded, too few records for a result
Huron County
Recorded, too few records for a result
Jackson County
Recorded, too few records for a result
Jefferson County
Recorded, too few records for a result
Knox County
Recorded, too few records for a result
Lake County
48 · Recorded, season not shown
Lawrence County
Recorded, too few records for a result
Licking County
40 · Recorded, season not shown
Logan County
Recorded, too few records for a result
Lorain County
47 · Recorded, season not shown
Lucas County
41 · Recorded, season not shown
Madison County
Recorded, too few records for a result
Mahoning County
38 · Recorded, season not shown
Marion County
Recorded, too few records for a result
Medina County
29 · Recorded, season not shown
Meigs County
Recorded, too few records for a result
Mercer County
No qualifying records yet
Miami County
Recorded, too few records for a result
Monroe County
Recorded, too few records for a result
Montgomery County
71 · Recorded, season not shown
Morgan County
Recorded, too few records for a result
Morrow County
Recorded, too few records for a result
Muskingum County
Recorded, too few records for a result
Noble County
Recorded, too few records for a result
Ottawa County
24 · Recorded, season not shown
Paulding County
No qualifying records yet
Perry County
Recorded, too few records for a result
Pickaway County
Recorded, too few records for a result
Pike County
Recorded, too few records for a result
Portage County
71 · Recorded, season not shown
Preble County
Recorded, too few records for a result
Putnam County
No qualifying records yet
Richland County
Recorded, too few records for a result
Ross County
Recorded, too few records for a result
Sandusky County
Recorded, too few records for a result
Scioto County
Recorded, too few records for a result
Seneca County
Recorded, too few records for a result
Shelby County
No qualifying records yet
Stark County
69 · Recorded, season not shown
Summit County
232 · Recorded, season not shown
Trumbull County
Recorded, too few records for a result
Tuscarawas County
Recorded, too few records for a result
Union County
Recorded, too few records for a result
Van Wert County
Recorded, too few records for a result
Vinton County
Recorded, too few records for a result
Warren County
42 · Recorded, season not shown
Washington County
Recorded, too few records for a result
Wayne County
38 · Recorded, season not shown
Williams County
Recorded, too few records for a result
Wood County
38 · Recorded, season not shown
Wyandot County
No qualifying records yet
No mapped range from the range source used, the USGS Gap Analysis Project, which maps land vertebrates only.
Season
When it is recorded
In Delaware County
Not enough evidence
The weeks are still too uncertain to show a season. Based on 97 records in 9 of the 10 years from 2016 to 2025, above the minimum of 20 records from 5 different years.
JanFebMarAprMayJunJulAugSepOctNovDec
Show over the bars
Recording in Delaware County · records of all species each week, 21,087 in all
Records per week from 97 records in 9 of the 10 years from 2016 to 2025. Shows when people recorded it, not a season or how common it is.
Show as a table
Records of eastern poison ivy in Delaware County each week, and records of all species
Week
Records of eastern poison ivy
Years recorded
Records of all species
Jan 4–10
0
0
75
Jan 11–17
0
0
35
Jan 18–24
0
0
37
Jan 25–31
0
0
28
Feb 1–7
0
0
33
Feb 8–14
0
0
56
Feb 15–21
0
0
38
Feb 22–28
0
0
36
Mar 1–7
0
0
73
Mar 8–14
0
0
118
Mar 15–21
0
0
111
Mar 22–28
0
0
120
Mar 29 – Apr 4
0
0
208
Apr 5–11
0
0
304
Apr 12–18
3
2
810
Apr 19–25
0
0
622
Apr 26 – May 2
1
1
561
May 3–9
1
1
539
May 10–16
4
4
620
May 17–23
7
4
560
May 24–30
8
5
640
May 31 – Jun 6
3
2
751
Jun 7–13
5
4
746
Jun 14–20
0
0
593
Jun 21–27
3
3
623
Jun 28 – Jul 4
1
1
725
Jul 5–11
5
3
597
Jul 12–18
3
3
785
Jul 19–25
0
0
848
Jul 26 – Aug 1
3
3
646
Aug 2–8
2
2
665
Aug 9–15
2
1
612
Aug 16–22
0
0
684
Aug 23–29
2
1
775
Aug 30 – Sep 5
3
1
782
Sep 6–12
6
6
1,111
Sep 13–19
9
4
827
Sep 20–26
9
3
663
Sep 27 – Oct 3
3
2
686
Oct 4–10
9
4
576
Oct 11–17
2
1
411
Oct 18–24
2
2
350
Oct 25–31
0
0
245
Nov 1–7
1
1
181
Nov 8–14
0
0
112
Nov 15–21
0
0
101
Nov 22–28
0
0
93
Nov 29 – Dec 5
0
0
55
Dec 6–12
0
0
39
Dec 13–19
0
0
56
Dec 20–26
0
0
39
Dec 27 – Jan 2
0
0
86
Reported in flower
Only 1 records here show flowers, too few to show a flowering season. One needs at least 20 records from 5 different years.
Reported in fruit
Only 6 records here show fruit, too few to show a fruiting season. One needs at least 20 records from 5 different years.
In Ohio
Late April to late October, middle week Jul 12–18
Middle week · Jul 12–18
This week · Nov 8–14
JanFebMarAprMayJunJulAugSepOctNovDec
Show over the bars
Recording in Ohio · records of all species each week, 1,691,199 in all
Records per week from 3,385 records in 10 of the 10 years from 2016 to 2025. Shows when people recorded it, not how common it is. The grey bars show how many records of all species were made here each week, so you can see when recording itself was high or low; the season is not adjusted by them.
Recorded on 1,373 dates. Latest record: December 2025.
Show as a table
Records of eastern poison ivy in Ohio each week, and records of all species
Week
Records of eastern poison ivy
Years recorded
Records of all species
Jan 4–10
1
1
6,211
Jan 11–17
1
1
5,146
Jan 18–24
1
1
4,645
Jan 25–31
5
5
4,698
Feb 1–7
16
8
6,023
Feb 8–14
8
5
5,888
Feb 15–21
13
4
5,436
Feb 22–28
1
1
6,846
Mar 1–7
14
4
8,321
Mar 8–14
9
4
10,384
Mar 15–21
7
4
12,620
Mar 22–28
2
2
13,949
Mar 29 – Apr 4
6
4
19,661
Apr 5–11
8
4
26,860
Apr 12–18
15
6
39,925
Apr 19–25
36
8
41,623
Apr 26 – May 2
126
10
56,391
May 3–9
154
10
52,952
May 10–16
140
8
53,785
May 17–23
180
10
57,698
May 24–30
206
10
54,651
May 31 – Jun 6
123
10
53,099
Jun 7–13
120
10
53,700
Jun 14–20
138
9
56,625
Jun 21–27
87
10
55,361
Jun 28 – Jul 4
84
9
58,477
Jul 5–11
91
10
61,336
Jul 12–18
104
10
64,722
Jul 19–25
87
9
69,753
Jul 26 – Aug 1
68
10
59,416
Aug 2–8
83
10
59,712
Aug 9–15
79
10
55,994
Aug 16–22
65
9
54,328
Aug 23–29
100
10
51,772
Aug 30 – Sep 5
164
9
57,167
Sep 6–12
109
10
59,075
Sep 13–19
128
10
54,543
Sep 20–26
109
10
45,860
Sep 27 – Oct 3
170
10
43,180
Oct 4–10
153
10
37,841
Oct 11–17
109
9
30,824
Oct 18–24
71
10
21,156
Oct 25–31
71
9
19,021
Nov 1–7
36
8
14,172
Nov 8–14
10
7
12,621
Nov 15–21
11
5
7,965
Nov 22–28
19
7
8,136
Nov 29 – Dec 5
16
7
6,083
Dec 6–12
9
4
6,004
Dec 13–19
5
2
5,423
Dec 20–26
7
4
5,661
Dec 27 – Jan 2
10
5
8,459
Reported in flower
Only 11 records here show flowers, too few to show a flowering season. One needs at least 20 records from 5 different years.
Reported in fruit
Usually reported in fruit late May to early August, middle week mid-July. A later season is not shown: the weeks are still too uncertain.
What these results show
These results show when people recorded a species, not when or where it occurs. Missing weeks and low counts do not mean absence or scarcity, and counts are not abundance. Contributed records reflect where, when and what people chose to observe.
Identification
How to identify it
Telling it apart
From what Ohio’s records show. Only what the records support is shown.
box elderAcer negundoOften confused in Ohio: 75 identifications in Ohio named one where the other was meant
Virginia creeperParthenocissus quinquefoliaOften confused in Ohio: 58 identifications in Ohio named one where the other was meant
fragrant sumacRhus aromaticaOften confused in Ohio: 14 identifications in Ohio named one where the other was meant
Japanese creeperParthenocissus tricuspidata193 identifications worldwide named one where the other was meant
wild sarsaparillaAralia nudicaulis169 identifications worldwide named one where the other was meant
From iNaturalist’s similar-species counts, refreshed monthly: confusions in Ohio first, then worldwide. Only species with an Ohio result are listed.
Land cover where it is recorded
Land cover
Its recordsAll Ohio records
Developed
50%49%
Forest
38%31%
Farmland
7%11%
Wetland
3%5%
Open water
0.9%3%
Grassland and shrub
0.5%0.9%
Barren
0.2%0.6%
From 2,214 records placed within 100 m, beside all Ohio records placed the same way. People record where they go, so this shows where records come from, not where the species lives. Land cover: USGS Annual NLCD, 2025 (opens in a new tab)
Finer identifications
Some Ohio records of this species were identified to a subspecies:
Every one of these records counts toward eastern poison ivy's season above.
Why some records go further than species
Many plants vary from place to place. Botanists name these groups at three levels below species: subspecies, variety and form, from the broadest difference to the smallest. Observers and experts only identify a record that far when it shows enough detail to tell them apart. Records without that detail count at the species level.
Names: Catalogue of Life.
Sources
Where these results come from
Records from iNaturalist research-grade observations and expert-identified GBIF datasets, CC0, CC BY and CC BY-NC. Sources
Seasons use the published method and its evidence thresholds. Methods
A spreadsheet (CSV) with a link to each record, on iNaturalist or GBIF. Records whose location was hidden by the observer or the source are counted but not linked.
