Molokai Native Hawaiian Beginning Farmer Program
1
Growing Vegetable Seedlings
Alton S. Arakaki, County Extension Agent
Growing healthy seedlings is the first step towards producing health adult plants and
getting the expected production out of the crop. It is well known by farmers that poorly
grown seedlings will increase the chances of producing poor yielding crops. Plants
without vigorous growth will also be more susceptible to insect and disease infections,
and will be less competitive to weeds.
Seedling Growing Environment
Moisture and temperature play key roles for vegetable seed germination. Seeds will not
germinate under cool and/or dry conditions. Most vegetables, melons, squashes,
tomatoes, cabbages and lettuces have optimum germination temperature range of 75 to
85 degrees F. Cooler or hotter temperatures will delay or may cause seeds not to
germinate. Sown seeds should be in contact with moisture consistently. Both optimum
temperature and moisture will trigger germination response of the seeds.
Once seeds germinate, moisture can be reduced to keep the media around the seedling
moist and not soggy wet. Over watering can enhance conditions for plant diseases and
reduce oxygen level in the media. All plant roots require oxygen to function. If the
seedling nursery is under direct sun light and high temperatures, seedlings should be
moved to a semi-shaded area. 45% shade-cloth over the seedling will help prevent
seedling heat-stress and sun burns on the young plants. Acclimating seedlings to field
sun conditions should begin 10-14 days prior to transplanting, beginning with ½ of
morning sun and gradually increasing to full day sun. As you increase the sun
exposure, you need to moni tor the moisture in the media. Higher temperatures and
windy conditions will increase the evapo-transpiration rate of the media and seedlings.
Seedling Trays
You can grow seedlings in seedling beds in your garden, but you will have better control
of your seedlings health if they are grown in seedling trays. The size of the tray and the
growing cells will vary according to the crop grown. Small and slower growing plants
are grown in smaller growing cells, while larger and faster growing plants are grown in
larger growing cells.
This project was supported by the Beginning Farmer and Rancher Development Program of the National Institute of Food
and Agriculture, USDA, Grant # 2009-03896. The University of Hawaii College of Tropical Agriculture and Human
Resources and the Cooperative Extension Service is an equal opportunity/affirmative action Institution providing
programs and services to all people of Hawaii without regard to race, sex, gender identity and expression, age, religion,
color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a
covered veteran.
Molokai Native Hawaiian Beginning Farmer Program
Crop
Tomato
Pepper
Eggplant
Lettuce
Broccoli
Cucumber
Watermelon
Cell Size (inches)
¾ to 1
¾ to 1
¾ to 1
¾ to 1
¾ to 1
1½
1½
2
Transplant (weeks after seeding)
4 to 5
6
6
3 to 4
4
2
2
Media
Store bought “ready-to-use” potting media is the simplest to use. Most commercial
media mixes are sterile, free of nematodes, diseases, and grass seeds. Some are pH
balance and others have fertilizer mixed in them. You can mix your own by purchasing
individual additives such as peat moss, perlite or vermiculite. Or you can use media you
have around your home, soil, sand, manure, compost or organic mulch. When using
home potting medium, you will need to work out your own recipe, because each soil,
manure and compost will have different texture and nutritional value that will affect the
final media composition.
50 qt.
4 c.
2 c.
Mixture #1
Ready to use potting
media
14-14-14 slow release
fertilizer (osmocote)
Lime or calcium
carbonate or coral
25 qt.
Mixture #2
Peat moss
16 qt.
25 qt.
Perlite or vermiculite
16 qt.
5 qt.
Sand (coral beach sand) 16 qt.
Mixture #3
Soil
Humus/organic mulch/
compost/
cured manure
Sand
4 c.
14-14-14 slow release
4 c.
14-14-14 slow release
fertilizer
fertilizer
(osmocote)
(osmocote)
Mixture #1- Table of Equivalence
Additives
Equivalence Equivalence Equivalence Equivalence Equivalence
Ready-to-Use Potting Media
50#1qt.
25#2qt.
12.4
4 qt. #4
(1 gal)
1#5
qt.
#3qt.
14-14-14 Slow release fertilizer
4 c.
2 c.
1 c.
2.6 fl. oz
.65 fl.oz, or
5 Tbsp
19.22 ml or
4 tsp
Lime or calcium carbonate or coral
2 c.
1 c.
½ c.
1.3 fl. oz. .32 fl.oz. or
9.46 ml or
2 tsp
This project was supported by the Beginning Farmer and Rancher Development Program of the National Institute of Food
and Agriculture, USDA, Grant # 2009-03896. The University of Hawaii College of Tropical Agriculture and Human
Resources and the Cooperative Extension Service is an equal opportunity/affirmative action Institution providing
programs and services to all people of Hawaii without regard to race, sex, gender identity and expression, age, religion,
color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a
covered veteran.
Molokai Native Hawaiian Beginning Farmer Program
3
Measurement Key
1 pt.=473 ml
1 pt=2c.
1 c=8 fl. oz
1 fl. oz.=2 Tbsp
1 Tbsp=3 tsp
1 tsp=.333
Tbsp
1 c.=236 ml
1 fl. oz.=29.5 ml
This project was supported by the Beginning Farmer and Rancher Development Program of the National Institute of Food
and Agriculture, USDA, Grant # 2009-03896. The University of Hawaii College of Tropical Agriculture and Human
Resources and the Cooperative Extension Service is an equal opportunity/affirmative action Institution providing
programs and services to all people of Hawaii without regard to race, sex, gender identity and expression, age, religion,
color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a
covered veteran.