Skip to content
SUS Farms — Allegedly Organic
← Back to Utah Gardening

Diagrams & reference charts

Visual references that pair with the guides — frost map, soil pH ranges, raised-bed cross-section, IPM pest calendar.

Tool 1

Utah frost map

NLast frost across UtahPlant after the date for your elevation. Color shows USDA hardiness zone.St. George · Mar 25 · Zone 8aSt. GeorgeMar 25 · 2,860 ftHurricane · Apr 5 · Zone 7bHurricaneApr 5 · 3,258 ftCedar City · May 22 · Zone 6aCedar CityMay 22 · 5,846 ftRichfield · May 18 · Zone 6aRichfieldMay 18 · 5,341 ftSevier County (SUS) · May 15 · Zone 6aSevier CountyMay 15 · 5,400 ftSalt Lake City · Apr 26 · Zone 7aSalt Lake CityApr 26 · 4,226 ftSandy · May 1 · Zone 7aSandyMay 1 · 4,470 ftProvo · May 5 · Zone 6bProvoMay 5 · 4,551 ftLogan · May 22 · Zone 5bLoganMay 22 · 4,534 ftPark City · Jun 15 · Zone 5aPark CityJun 15 · 7,000 ftVernal · May 28 · Zone 5bVernalMay 28 · 5,331 ftMoab · Apr 22 · Zone 7aMoabApr 22 · 4,026 ftUSDA Zone5a5b6a6b7a7b8a

St. George

Z 8a

2,860 ft

Last spring

Mar 25

First fall

Nov 5

Hurricane

Z 7b

3,258 ft

Last spring

Apr 5

First fall

Oct 28

Cedar City

Z 6a

5,846 ft

Last spring

May 22

First fall

Sep 28

Richfield

Z 6a

5,341 ft

Last spring

May 18

First fall

Oct 1

Sevier County

Z 6a

5,400 ft

Last spring

May 15

First fall

Oct 5

Salt Lake City

Z 7a

4,226 ft

Last spring

Apr 26

First fall

Oct 22

Sandy

Z 7a

4,470 ft

Last spring

May 1

First fall

Oct 18

Provo

Z 6b

4,551 ft

Last spring

May 5

First fall

Oct 12

Logan

Z 5b

4,534 ft

Last spring

May 22

First fall

Sep 30

Park City

Z 5a

7,000 ft

Last spring

Jun 15

First fall

Sep 5

Vernal

Z 5b

5,331 ft

Last spring

May 28

First fall

Sep 22

Moab

Z 7a

4,026 ft

Last spring

Apr 22

First fall

Oct 24

Tool 2

Soil pH scale

Soil pH — what Utah gives you, what crops want456789Native Utah soil (7.4–8.4)Blueberries4.5–5.5Potatoes5–6.5Strawberries5.5–6.8Raspberries5.6–6.5Tomatoes6–6.8Peppers6–6.8Corn5.8–7Cucurbits6–7.5Brassicas6–7.5Asparagus6.5–7.5Most lawns6–7.5Native Utah pH overlapsNeeds amendment

Tool 3

Raised-bed cross-section

Raised bed cross-sectionUSU Extension specs · 48" wide × 12" deepLoosened native soil (broadfork to 6" below grade)50% topsoil · 30% compost · 10% sand · 10% peatTotal mix volume: 29 ft³ per 4' × 12' bed2" straw or wood-chip mulchdrip line48" — arm-reach from both sides12"Edging: untreated cedar or redwood. Avoid pressure-treated lumber and railroad ties — both leach into food crops.Length: keep under 12 ft, or kids and dogs will use the bed as a shortcut.

Recommended mix

50%

Topsoil

30%

Compost

10%

Sand or perlite

10%

Peat or coir

Tool 4

Soil amendments table

AmendmentRateWhenWhy
Compost (annual top-dress)1–2 inchesLate fall or early springBuilds organic matter, holds water, feeds soil biology.
Elemental sulfur1 lb / 100 sq ft6+ months before plantingLowers pH 0.5 unit. Repeat applications needed for stubborn caliche soils.
Aged manure0.5–1 inchFall (must age before planting)Nitrogen and biology. Never use fresh — burns roots and may carry weed seed.
Iron chelate (Sequestrene 138)Per label, foliarWhen chlorosis appearsQuickest fix for iron-deficiency yellowing in alkaline soil.
Gypsum5 lb / 100 sq ftAnytimeLoosens clay-caliche soils. Does NOT lower pH despite the myth.
Cover crop (rye/vetch mix)2 oz / 100 sq ftSow Sept, terminate AprilAdds organic matter and fixes nitrogen over winter. Best long-term play.

Tool 5

IPM pest calendar

Mar

  • • Codling moth (set traps)
  • • Cabbage maggot

Pheromone traps in apples; row cover on brassicas.

Apr

  • • Aphid pressure starts
  • • Cherry slug
  • • Powdery mildew (early)

Beneficial release; horticultural oil dormant spray on stone fruit.

May

  • • Cucumber beetle
  • • Flea beetle on eggplants/potatoes

Floating row cover until flowering; trap crops.

Jun

  • • Squash bug
  • • Squash vine borer (lower elevations)
  • • Spider mite (heat)

Hand-pick squash bug eggs; mist undersides of leaves daily for mites.

Jul

  • • Tomato hornworm
  • • Earwig surge after irrigation
  • • Powdery mildew on cucurbits

Bt for hornworms; trap earwigs with rolled newspaper; spaced plantings.

Aug

  • • Grasshoppers (variable years)
  • • Late blight on tomatoes (wet years)

Nolo bait; remove infected tomato leaves.

Sep

  • • Codling moth second flight
  • • Vole damage starts

Pick up dropped fruit; clear weeds from tree bases.

Oct

  • • Mouse / vole prep

Mouse-proof tree guards; clean compost piles.