Catnip Growth Stages


Understanding catnip’s growth stages will help you raise your own with better success. What is the typical life cycle?
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Catnip is simple to cultivate, but it is always easier to grow when you know the different stages of its life cycle.

Recognizing the growth stages will help you identify issues as they happen. It will help you become a better gardener and the knowledge will also apply to a certain degree to other plants. 

In this article, I will cover the different phases of catnip development.

General Information

Catnip, or Nepera cataria, is an herbaceous perennial that is native to Eurasia and a member of the mint family (Lamiaceae).

Catnip plants mature to a height of 18 to 24 inches. It has pungent, coarsely-toothed, triangular to oval, grayish-green foliage that can grow up to 3″ long.

The taller stems end in compact whorls of flowers on spike-like racemes that can be 1-6 inches long. Tubular blossoms are small, two-lipped white flowers with slight purplish streaks. They blossom from May through September.

It was given the name catmint because of its strong scent, which cats find appealing.

Young flowers of a catnip plant in the garden

Seed Stage

The plant life cycle starts with a seed; every seed holds a miniature plant called the embryo. 

There are two types of flowering plant seeds: dicots and monocots. Catnip belongs to the dicot classification, which means it has a pair of leaves, or cotyledons, in the embryo of the seed.

An ounce of catnip seeds contains approximately 3,400 seeds. Catnip seeds are viable for 5 years.

Catnip seeds are considered easy to germinate and easy to grow. But like many perennial plants, higher germination rates may occur only after a period of stratification.

A person holding a tweezer to distribute seeds for paper germination

Germination

When the seeds are kept warm and moist, germination should occur within 5-10 days. 

After being planted in the soil for a few days, the seed absorbs water and swells until the seed coat splits. The stem pushes through the soil along with the cotyledons, or seed leaves. This process is known as germination or sprouting. 

At the same time, tiny roots push downwards, guided by gravity, searching for water and nutrients. 

planting seedlings on an egg carton

Growth

Early Development (First to mid-Spring)

Shoots emerge from existing catnip plants in early spring. These have thick, juicy stems that are frequently reddish or brownish in color.

They have luscious meaty green leaves with a lot of nepetalactone, and cats will go out of their way to find these young shoots if they can.

The floppy, fleshy stems at this time also contain some of the essential oils, which can be extracted through the process of distillation.

A healthy bush of catnip leaves

Rapid and Luxuriant Development (Late spring-early summer)

Plants grow and expand in tallness.

The plant contains the most nepetalactone and other chemicals at this stage. For this reason, this is the ideal time to collect catnip if you will be using it for medicinal reasons.

The stems become longer, thinner, and less bendable, and they begin to branch. Flower buds appear at the top of the stalks, followed by the formation of flowers.

Blossoms have relatively high amounts of nepetalactone at this stage, hence why flowering tops of catnip are desirable and frequently offered as ‘gourmet’ catnip.

purplepink flowers in the garden

Full Development (Mid Summer)

Plants can reach five feet in height and be covered in beautiful flowers at this stage.

They’ve grown to be exceedingly robust and woody. They could be a half-inch (13 mm) across at the base.

However, the leaves become dull-looking and may turn yellow or rusty. The leaves around the plant’s base turn dark and withered.

The flowers have lower nepetalactone levels than in the rapid development stage since some blooms have passed their peak and others are just starting to bloom.

At this stage, it’s far too late to harvest the majority of the catnip leaf. The rest of the stem is useless for medicinal or feline uses.

Blooming purple catnip flowers in the garden

Reproduction

Catnip blooms are little, fragrant, lip-shaped white or light lavender flowers with purple dots that grow in thick whorled clusters on the branches and stems. 

Flowers contain both reproductive organs. 

Catnip grows from spring to fall and is pollinated by insects. Catnip’s fruit is a pod with four oval, reddish-brown seeds. 

Catnip reproduces through seed and underground rhizomes.

Pollination

The catnip plant is self-pollinating.

Because the flowers lack secretory glands, they aren’t repulsive to the insects that pollinate them. The hue of the blossoms attracts insects, which are predominantly honeybees.

The nectaries of the immature flower produce nectar. 

The bees are sprinkled with pollen as they push into the blossoms for their nectar reward, which they then rub onto the stigma of the next flower they visit.

When pollen from another catnip plant is sprinkled on the stigma, it germinates and fertilizes the eggs.

Among the most common pollinators are honey bees (Apis mellifera), solitary bees (Halictidae), and bumble bees (Bombus spp.)

A bee pollinating on a purple catnip flower

Spreading Seeds

Seed spreading, or dispersal, is the final stage of the flower life cycle.

As the seeds mature, the petals fade, but the calyx (composed of the sepals that protect the bloom as a bud) becomes dry and rigid. 

Because the slender stalk that holds the calyx is elastic, the seeds are thrown into the air and land up to a 3 feet distant from the parent plant if an animal or another plant brushes against it.

This is why seedlings of plants in the Lamiaceae or Labiatae mint family may always be seen growing up at a safe distance.

Once the seeds fall to the ground, the plant life cycle starts all over again.

Alaine Connolly
Alaine has been working way too hard in horticulture since 1992, beautifying golf courses, resorts, and hotels. She is a part time landscape designer who works full time caring for a 28,000 square foot public garden. At home, she maintains her own 400 square feet plot. Alaine lives in northern Illinois - zone 5b.
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