Morning glories and moonflowers are closely related flowering vines that are often planted in tandem. Morning glory has purplish-blue flowers that bloom in the morning and early afternoon hours, and moonflower has white flowers that bloom in the evening and at night. While both these annual vines readily self-seed, collecting the seeds from the flowers allows you to expand the morning glory and moonflower bed to other areas of the garden without the expense of purchasing new seeds.
Check for seed pod formation once the flowers begin to wither. Morning glory pods are round and light to dark brown. Moonflower seed pods have spines on them and start green, then change to yellowish tan as they mature.
Pick the seed pods after they have darkened and dried but before they begin to split open. Wear gloves when harvesting moonflower to avoid being pricked.
Spread the pods out on a tray or baking pan in a warm, dry room. Leave the pods in the room to dry for an additional one to two weeks or until the pods begin cracking open.
Hold the pods over a bowl and pull them open. Shake the seeds out into the bowl. Morning glory typically has four seeds per pod, and moonflower has 20 or more seeds per pod.
Label a jar with type of seed and year harvested. Place the seeds in the jar and seal it closed. Store in the refrigerator until you are ready to plant in spring.