I'm looking for herbs and botanicals that will grow in hot, dry, salty conditions Salt Cay in Turks & Caicos Islands (Caribbean). My friend has tried basil thyme etc with little luck. Can you give me some strains of thyme, oregano, etc that would survive? Water is limited but available and potting soil and peat moss too. The island grows a form of heather possibly not a true relative.
A fair amount of research has been done to find trees and shrubs that are salt tolerant, but not too many herbaceous plants have been examined.
I don't think thyme will survive salty soil. No thymes have been listed in the lists of salt tolerant plants. Plants that are native to seashores may do fine.
If you want to grow herbs in the soil you have on your property, you should augment it with peat moss or compost to increase the water holding capacity and thus reduce watering requirement. Adding a good mulch is another "must do" in your conditions. For the herbs that cannot take drying out, but that you feel you must have, you will have to water regularly as well.
Another option is to grow them in planters with good drainage holes and filled with salt free commercial soil. Place them close to your hose so that watering is not a problem. If you experience salt spray, you may have to replace the soil periodically and in any case water with salt free water liberally from time to time, to wash out the accumulated salts. You can also use the shade the house makes to moderate the heat.
As seedlings many of the salt tolerant plants may not be salt tolerant. Therefore, protect seedlings or grow them in pots until they are mature and ready to go into their final locations.
You probably have a tropical climate and any plants that you want anyway, but cannot take that sort of heat may have to be grown indoors if you have air-conditioned temperatures. Those that I think would do well out of doors in your hot and dry climate are marked with an easterisk (*).
Here is a list of herbs that I have been able to find that are salt tolerant (S), moderately salt tolerant (MS), or slightly salt tolerant (SS). If the degree of salt tolerance was not indicated the code is (s). Few of these are popular cooking herbs; but don't let this discourage you too much, with containers, as suggested above, you can grow many salt-intolerant herbs with success.
Asparagus-s-(Asparagus officinalis) (Z5-9)#8022
Baby's Breath-S-(Gypsophila paniculata) (Z4-9)#7612
Bayberry-S-(Myrica pensylvanica) (Zone 5-9)#1298
*Beet, Sugar-S-(Beta vulgaris 'Saccherifera', annual #1340
Bilberry-S-(Vaccinium myrtillus)(Z2-7)#1410
Birch -MS-(Betula alba) #E1420
Blueberry-S-(Vaccinium angustifolium) (Z3-7)#1465
*Bo-Tree-S-(Ficus religiosa)(Z10B-11+)
Broom-S-(Cytisus sp such as scoparia), (Z6-8)#1525
Chaparral-S-(Larrea tridentata =L.mexicana)(Z7-9)#1710
*Chastetree-S-(Vitex agnus-castus)(Z7-10)#1712
Cinquefoil, Shrubs-S-(Potentilla sp.)(Z6-9?)
Colocinth-s-(Citrullus colocinthis)(annual)#1846(moist)
*Corn-s-(Zea mays)(annual)#8205-8212
*Daylily-MS-(Hemerocallis fulva and hybrida)(Z3-10)
Dianthus-S-(Dianthus sp.)(Z#4 or 5 to 8 or 9)01825, 4488, 6150
Elm, Slippery-S-(Ulmus, rubra) (Z4-9)Moist, shade!#2330
Eucalyptus -s-(Eucalyptus spp.)(Z9-10)#2360-2374(rich, well-drained)
Foxglove-S-(Digitalis sp)(Z3-4 to 8-10)#2730-2734, *2732
Ginkgo -S-(Ginkgo biloba), (Z5-9) #2862-500
*Guava, Pineapple-MS-(Feijoa sellowiana)(Z9-10)#3044
*Gumplant-s-(Grindelia robusta)(Z7-10)#3050
*Jojoba-s-(Simmondsia chinensis)(Z9-10)#3512
*Maikoa-s-(Brugmansia sp.)(Z10B-11+)#3840
Mint-s-(Mentha spp)(Z4-7 to 9-11)#400-4055(moist)
Natal Plum-S-(Carissa grandiflora)(Z9-10)#4258(Light shade)
*Neem-s-(Azadirachta indica)(Z11+) #4263
Night Jessamine-MS-(Cestrum nocturnum)(Z11+)#3508(sheltered)
Oregon Grape-MS-(Mahonia aquifolia)(Z5-8)#4318-500
Physic Nut-SS-(Jatropha curcas)(Z11+)#4479(moist)
*Prickly Pear-S-(Opuntia humifusa)(Z5-10)#4745
*Privet, Chinese-MS-(Ligustum lucidum)(Z7-10)#4751
Privet, Golden-MS-(Ligustrum vulgare)(Z5-9)#4752
*Purslane, French-S-(Portulaca oleracea sativa)(Annual)#8539-8540
*Quinoa-s-(Chenopodium quinoa)(annual)
Rose, Rugosa -S-(Rosa rugosa) (Zone 4-8)
Roses, Shrub -S- (R. various) (Z5-8 to 4-9)#5015-25
Rosemary-S- (Rosmarinus officinalis)(Z8-10)#5030-5039(never dry out)
St. John's Wort-S-(Hypericum perforatum), (Z4-8)#5195-6
*Samphire-s-(Crithmum maritinum)(Z8-10)#5198
Sea Lavender-MS-(Limonium latifolium)(Z4-9)#5373
Squaw Vine-SS to MS-(Mitchella repens)(Z5-9)#6020
Sumac, Sweet-S-(Rhus aromatica),(Z4-9) #6100
Tea Tree-s-(Melaleuca alternifolia)(Z11+)#6250(Moist to wet)
Uva Ursi-S-(Arctostaphylos uva-ursi), (Z2-8)#6565
Willow, Weeping -MS-(Salix babylonica) moist soil
Wormwood-MS-(Artemisia absinthium)(Z3-9)#6960
Wormwood, Powis Castle-MS-(A.abs.XA.arborescens)(Z6-9)#6977
Wormwood, Silver Mound-MS-(A. schmidtiana 'nana')(Z5-8)#6982
*Yarrow-S-(Achillea sp.)(Z2-7 to 8-10)#7000-7010
*Yucca -S-(Yucca filamentosa)