If you are just beginning with witchcraft and want to work with herbs, this is the herb you should start with. Of course, you can buy lavender plants but it is so easy to grow your own and I highly recommend doing this.
I have a lavender patch. The scent is just lovely and it attracts butterflies and bees.

A bit of history.
The herb lavender takes its name from the Latin lavare, which means to wash because the Romans used lavender in their bath water as well as for its therapeutic properties.
It was known that ancient Egyptians used lavender to make perfumes. Lavender was found within King Tutankhamun’s tomb when it was opened in 1922 and still retained some of its fragrance!
The Victorians loved lavender; it was seen in many gardens. It was folded between clothes to keep them fresh and was used in soap, cosmetics, and hair products. Lavender found its way into the Victorian kitchen too.It had many medicinal uses, being used to not only aid sleep but to ease depression and nerves.
home and hearth uses for lavender.
Lavender can be used to flavour food and drinks. It is great to burn after arguments and tantrums, as it has a calming effect.
Lavender in witchcraft.

I dry bundles of lavender to use in spells and rituals it can generally be substituted for any herb.
It is great to help lift your spirits and ease your mind. Of course, Lavender is good to help aid sleep. See how to make our lavender sleep spray here.
Use in rituals for love, protection, sleep, purification, happiness, and peace. It is a must for your witches’ storecupboard.

Kew – Witch’s Garden: Plants in Folklore, Magic and Traditional Medicine by Sandra Lawrance.
The Celestial Garden : Growing Herbs, Vegetables, and Flowers in Sync with the Moon and Zodiac