Orach also known as Mountain spinach, French spinach, Giant Lambs quarters. Touted as a warm-season alternative to spinach, orach is actually a cool-season plant that just doesn't go to seed (bolt) as quickly as spinach. Harvest leaves that are less-bitter than spinach into the summer.
Orach is generally disease and garden pest resistant. Occasionally there may be Aphids gathering on the underside of leaves. Use garden hose water to blast off aphids early in the morning. Keep an eye out for the larvae of lady beetles and lacewings. Though not common, you may have to pull a few of them out of the soil occasionally.
If the orach plants are tightly spaced, harvest them all the way down to one or two inches above the soil. Once they grow back up, you’re ready to harvest again for fresh salads and greens. If you thinned out your rows up to 12 inches apart early during grow period, you could now choose to thin them up to 18 inches, or you can keep them as they are.
When harvesting from fully grown orach plants, wait until the plant has fully matured, then leave the older leaves in place and begin regularly harvesting the younger leaves so that the orach stays healthy and focused on new growth. Pinch off flower buds to encourage branching and promote new growth.