HA means hardy annual. This is a seed you can grow outside and scatter in situ.

HHA means half hardy annual. You’ll have to start this seed inside the house, and then plant it outside.

HP means hardy perennial. You should know whether this perennial will grow well in your area.

HHP means half hardy perennial. It’s a perennial that will do well in warmer climates but will probably be an annual in cold areas.

10 Thriftiest Perennials for the Sun

1. Sandwort (Arenaria “Wallowa Mountains"
2. Gysophila (Gypsophila aretiodes) 
3. Speedwell
4. Andosace
5. Draba
6. Moss campion or catchfly
7. Gentian
8. Dwarf daphne
9. Daphne
10. Fleabane

10 Thriftiest Perennials for Shade

1. Hosta ‘Mt Kirishima'
2. Lungwort
3. Primrose
4. Allioni’s primrose
5. Pyrenean violet Ramonda myconi
6. Resurrection plant Haberlea rhodopensis
7. Saxifrage
8. Stonecrop 
9. Maindenhair spleenwort Asplenium trichomanes
10. Shooting star Dodecatheon pulchellum

Avoid False spirea Sorbaria sorbifolia