Desert Pipevine - these seed capsules are ready for harvest when the triangular seeds inside are black and the surrounding capsule is brown. An easy way to collect the seeds is when the capsules have split open and spilled the seeds in a pile onto the ground. Rodents may nibble the blossom end of a green capsule open but the seeds are poisonous and the rodents will not do any lasting harm.

Four O'Clock family - the leaf-like covering on the seeds can be carefully opened to reveal the black seeds inside. Desert Four O'Clock will have four to six seeds per capsule. Sweet Four O'Clock will have one one-quarter inch (6 mm) diameter seed per capsule. The leaves and stems of the Sweet Four O'Clock will be slightly sticky. If the seeds are not rolling freely inside their covering, they are not ripe.

Legumes such as Fern Acacia and Yellow Bird of Paradise - when some seed pods have opened on the plant, check other pods and find ones that are brown or reddish on both sides with no green. They must be attached a stem that is brown and not green. Tap the pod with a finger and you will hear the seeds inside rattle. Remove the pod and put it in your collection bag or bottle. Don't be surprised if you hear the seed pods open with a snap in your bag. That indicates that you harvested the pods just in time.

Morning Glory vines including Scarlet Creeper - check the vine when most of the flowers have stopped blooming but some flowers are still left. These seed capsules ripen very quickly, so check for small, brown, round capsules. When you find one, put a collecting bottle underneath and gently twist the capsule between two fingers. If the capsule is ripe, the four small black seeds will fall out. Visit the vine every day for several days. There will be many seed capsules in various stages of ripeness. The light-weight sides of the seed capsule that fall in the collecting jar can be carefully blown away leaving the seeds behind.

Pink Fairy Duster - it is impossible to predict when these seed pods will open. To collect seeds, place a tea bag around the pod with the stem end tied securely. Check the plant every day. When the pod is ripe, it will snap open suddenly, throwing seeds in all directions. Do not use a plastic bag: it causes a heat buildup that will kill the ripening seeds. Fairy Duster plants need regular water to have a good seed germination rate.

Redwhisker Clammyweed - wait until the upward-pointing pods and stems turn brown. The pods open at the end when they are ripe, allowing seeds to fall out on a windy day. Carefully cut the brown stem of the pod and place the entire pod in a container.
The biggest problem with these pods is that many of them have been infested with insect larvae which have eaten the seeds. If a pod has a small round hole on its side, discard it. A few pods will have healthy round seeds. Others will contain mostly dust indicating an insect has been there first.

Slim Pod Senna - these are among the easiest seeds to collect. The long slim pods will turn brown and start to split lengthwise. Carefully cut the brown stem of the pod and place the entire pod in a bag. Open the pod in the bag to release the seeds, which resemble gray cylindrical pellets.