When to Plant Desert Garden Seeds: They shouldn’t all be planted at the same time

Seeds need to be planted far enough in advance of the time they will be transplanted into the garden. The time frame can be anywhere from four weeks to over four months depending on how long the seeds need to germinate, the rate of growth of the plant, and outside conditions, like precipitation and temperature.

 

 

One of the biggest mistakes beginning (and some seasoned gardeners as well) make is sowing seeds too early. The seeds germinate, and begin to grow, but outside conditions are not right to transplant them into the garden. As a result, the plants will get long and leggy or become stunted.

One of the best guides as to when to plant seeds for transplanting is the USDA Cold-Hardiness Zone map.

When to plant

Some favorite and more common plants for desert gardens have varying requirements for planting. Here are some guidelines:

You should seed the following plants 12 weeks or more before the last spring frost:

Begonias

  • 10-15 days to germinate
  • 70 degrees F germination temperature
  • Light (germination in light or dark)

Geranium

  • 10-20 days to germinate
  • 70 degrees germination temperature
  • Light

Larkspur

  • 5-10 days to germinate
  • 55 degrees germination temperature
  • Dark

Pansy

  • 5-10 days to germinate
  • 65 degrees germination temperature
  • Dark

The plants below should be seeded 10 weeks before the last spring frost:

Dianthus

  • 5-10 days to germinate
  • 70 degrees germination temperature
  • Either light or dark

Impatiens

  • 15-20 days to germinate
  • 70 degrees germination temperature
  • Light

Petunia

  • 5-10 days to germinate
  • 70 degrees germination temperature
  • Light

Portulaca

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Dark

Snapdragon

  • 5-10 days to germination
  • 65 degrees germination temperature
  • Light

Verbena

  • 15-20 days to germination
  • 65 degrees germination temperature
  • Dark

The following plants should be sown eight weeks before the last spring frost:

Alyssum

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Light or dark

Brocolli

  • 5-10 days to germination
  • 70 degrees
  • Either

Cabbage

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Either

Cauliflower

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Either

Eggplant

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Either

Pepper

  • 5-10 days to germination
  • 80 degrees germination temperature
  • Either

The plants below should be sown six weeks before the last spring frost:

Aster

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Either

Marigold

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Either

Tomato

  • 5-10 days to germination
  • 80 degrees germination temperature
  • Either

The plants below should be sown four weeks or less before the last spring frost:

Cucumber

  • 5-10 days to germination
  • 85 degrees germination temperature
  • Either

Cosmos

  • 5-10 days to germination
  • 70 degrees germination temperature
  • Either

Canteloupe

  • 5-10 days to germination
  • 85 degrees germination temperature
  • Either

Squash

  • 5-10 days to germination
  • 85 degrees germination temperature
  • Either

Please understand that this is not an exhaustive list. For a full list of plants and cold hardiness zones, please see the National Arboretum website.