Grosso Lavender poses as an interesting lavender variant to grow. It is appealing, fragrant, and quite hardy! It fuses all the desirable characteristics of English lavender and French lavender into one plant.
You should Grow ‘Grosso’ Lavender in full sunlight, with low fertility fertile soil, and do not provide shade or fertilizer. Avoid moist soil and high humidity.
To get the amazing flowers and aroma of ‘Grosso’ Lavender, you must provide ALL of the following conditions.
Intense Sunlight required for Grosso Lavender
For all plants, sunlight is the key component that enables the process of photosynthesis. Without it, plants cannot grow and produce food materials.
When it comes to lavender, sunlight does more than produce food. The powerful sun rays are responsible for deciding the fate of the flowers.
Sunlight directly influences the color and flower output of this Lavender and all lavenders for that matter.
At a minimum, ‘Grosso’ Lavender should receive no less than 6 hours of sunlight. Plant them in the sunniest spot in the garden.
Don’t have a sunny garden area? The next best thing is to grow them in pots and place them on a sunny window.
Keeping with French lavender’s high sunlight requirement, ‘Grosso’ Lavender needs full sun! Trying to provide them with shade will not work. Sunlight also happens to be the dominating climate from the place where these lavenders originate.
Being partly a French lavender, ‘Grosso’ Lavender is renowned for its attractive flowers.
Full sunlight is likely to yield the best results for your lavender plants. This applies in terms of growth, flowering, and oil production (for aroma).
Having enough sunlight coverage also goes a long way in avoiding excessive moisture in both the air and soil.
Infections caused by highly humid air will have fewer chances of being initiated if the air is always dry enough.
‘Grosso’ Lavender Soil Requirements
There are usually shared soil requirements across all lavender variants. The only difference comes in the soil pH each variety can tolerate.
When it comes to ‘Grosso’ Lavender, the ideal soil should have a pH between 6.5 and 7.5 This means soil that is mildly acidic to alkaline is best for growing this hybrid lavender variant.
What are the other soil requirements of ‘Grosso’ Lavender? Let’s find out.
There are requirements relating to the soil’s drainage capacity and its nutrient levels.
Lavender is not a water greedy plant and having water ‘at its feet’ does not go well.
The soil has to be such that water almost immediately seeps through. It certainly shouldn’t be the type of soil that creates puddles and pools.
To ensure the soil has the best draining capacity, choose a soil with 70% compost and 30% sand/grit. ‘Grosso’ Lavender (or any lavender) will not do well in clay soils.
Most soil from which lavender originates and grows easily is majorly composed of sand or grit.
Such soils are common in Southern Europe where lavender grows freely without any external interference from humans.
At this point, you must be thinking about how exactly does moisture-retaining soil affect ‘Grosso’ Lavender?
Poor soil drainage can result in wet soil around the roots.
This increases the chances of the lavender plants developing a serious condition called root rot.
Roots affected by root rot usually have a grim prognosis which will also affect the livelihood of the lavender plant.
Plus, if the moisture manages to make it into the air between plants, such an environment could invite fungal growth. In turn, the plants would risk fungal infections.
Both instances could pose a threat to your lavender plants not just stunting their growth but also possibly killing them.
Fertile soil is usually essential for most garden plants.
But traditionally, lavender is not a garden plant even though this Lavender is a genetically modified hybrid lavender. All lavenders prefer soils that are not fertile and not artificially enhanced.
Your ‘Grosso’ Lavender will appreciate and flower best in soils of low to medium fertility. Soils with high amounts of sand/grit/perlite will help to improve the flowering potential of your lavender plants.
Overly fertile soil will greatly affect your lavender by drastically reducing its ability to flower. In some cases, fertile soil can stimulate leggy green plant growth at the expense of flowers.
There is nothing more disappointing than a lavender plant without flowers! Especially after you have seen the amazing flowering capacity of ‘Grosso’ Lavender.
So if you really want bountiful lavender flowers, avoid using any form of chemical fertilizer and compost materials.
How much to Water Grosso Lavender?
Do you want healthy ‘Grosso’ Lavender that flowers according to the high expectations people have come to expect from it?
Well then if your answer is yes, you must pay careful attention to how you water these plants.
All lavenders are very sensitive to water and excess amounts can end your plant without you suspecting water as the culprit! Overwatering is a silent yet deadly condition and the leading cause behind lavender plant death.
Sometimes people who attempt to grow this lavender variant mistake wilting or yellowing as a sign of lack of watering. Therefore sticking to a strict watering schedule should be your approach to watering your lavender plants.
Keep the watering efforts to a minimum. Ideally, you should only water your lavender plants once every two weeks! But that’s only if they are established mature lavender plants.
‘Grosso’ Lavender does not like too much water and so you are better off providing drought-like conditions for them.
How Often To Water ‘Grosso’ Lavender In Winter?
All plants including lavender enter a state of dormancy when winter arrives.
So, understandably lavender plants will not need much water. Perhaps no water at all! Luckily, ‘Grosso’ Lavender is tolerant to USDA zones 5 to 10, this includes some frost and cold.
When left outdoors, the air and soil will contain more than enough moisture to sustain the needs of the plants.
Completely cease all watering efforts in winter if you are in a cold climate. But, if you are in an area where winters are almost absent, water your ‘Grosso’ Lavender once or twice in winter.
Watering New Grosso Lavender Transplants
Just finished transplanting, repotting, or transferring your lavender plants? In that case, minding your watering will be vital for the plant to successfully re-establishing its root system.
Initially, when undergoing this process, the new plants are at increased risk of stress due to transplant shock.
But with careful watering efforts and care, you can mitigate the risks associated with transplanting. As soon as replanting the ‘Grosso’ Lavender is complete, offer them a soaking! That is a generous watering immediately.
Over the next week, water it every second day. Then for the next few months adopt a watering schedule of every 3 or 4 days. Following the conclusion of this watering schedule, revert to watering once every two weeks.
Watering Potted ‘Grosso’ Lavender
Since it is a French lavender hybrid, these plants flower beautifully, are smaller, and are less cold hardy. As a result, growing them indoors in pots is desirable.
Of course, potted lavender needs a different watering plan than the one that applies to grounded lavender.
Water potted ‘Grosso’ Lavender once every two weeks in the growing season (summer). In extremely hot temperatures, water once every 10-14 days depending on how quickly the pot and soil dries.
Whether you choose the 10 days or 14 days interval depends on how porous the soil is, the weather, and the potting material.
Adequately Spacing Your ‘Grosso’ Lavender
Plant your ‘Grosso’ Lavender too close together and you are setting them up for disaster. Although they may look appealing when planted close together, ill effects will soon reveal themselves.
Inadequate lavender spacing can cause:
- Fungal infections
- Resource limitations
- Sunlight shortages
- High humidity (moist soil)
- Inadequate space for foliage to fully flourish
‘Grosso’ Lavender is by no means a small plant. They are among the largest lavender plants. They reach a mature size of 32 inches (80 cm) in height and 46 inches (116 cm) in width!
To ensure the best growth and flowering, space each plant 2-3 feet away from the next plant.
A one-foot distance will not be enough seeing as ‘Grosso’ Lavender gets quite wide. There would not be enough space to let the sunlight shine through and dry the air and soil.
After all, you should be recreating a drought-like atmosphere.
Plus the worst thing would be to have plants grow into each other. As a result, separating or transplanting them would prove to be very difficult.
Lack of resources would eventually mean both plants will be drastically affected.
Of course, potted ‘Grosso’ lavender plants can’t be given too much space. But that means you should plant fewer in the pot.
Does ‘Grosso’ Lavender Need Pruning?
Yes, this lavender variant definitely needs pruning! Gardeners will have high flowering expectations from this lavender hybrid since it does share genes with the famous French lavender.
Pruning efforts will go a long way in making the plant flower up to the high hopes people carry. The activity of pruning will promote the shooting of stems.
It is from these stems (new growth) that flower buds and flowers will emerge in summer.
But that’s not all pruning helps you accomplish. ‘Grosso’ Lavender is a big plant that can get out of control if neglected for too long.
Constant pruning will keep your plants neat and appealing. A flowering bushy lavender is not as attractive as a flowering trimmed lavender plant.
Want your lavender to be more tolerant to cold and live longer? Well, pruning can help with that as well. It strengthens the basal stem and allows it to stay strong through winters.
Growing ‘Grosso’ Lavender In Pots
You can grow ‘Grosso’ lavender in pots/containers. They will actually take quite well to them because of the excellent drainage offered.
One word of caution is not to select the wrong pot. An inadequate pot can prevent proper growth which in turn affects flowering. Here are some guidelines to choose a pot for growing ‘Grosso’ Lavender.
- The pot should be made from a fast-drying material (clay/terracotta)
- Drainage holes should be present
- Avoid placing a drip tray below the pot
- Position the pot in an area receiving full sunlight
Apart from the pot, other requirements are the same as ‘Grosso’ Lavender planted in the ground in the garden. This includes:
Also, it is worth noting that these lavender plants get considerably large! They may outgrow their pot in a few years.
When Does Lavender ‘Grosso’ Flower?
‘Grosso’ Lavender’s flower timing is climate-dependent. States in the USA with various climates will see different blooming times.
Most ‘Grosso’ Lavender plants will flower during mid to late summer (July to August). Each bloom will last a few weeks, making for a colorful summer season.
Constant deadheading (spent flower removal) and pruning will ensure healthy flowers with each successive bloom.
If you have experience in growing other types of lavender, you shouldn’t have many problems growing lavender ‘Grosso’.
This lavender shares the same soil, watering, pruning, sunlight, and spacing requirements as most other English lavender plants.
When it comes to plant and flowering properties, it bears the best of French lavender and English lavender. You should have a breeze growing lavender ‘Grosso’.
This lavender can live between 5 and 10 years depending on the care you provide it with. Careful pruning can extend the plant’s life.
Yes, you can grow lavender ‘Grosso’ in pots if all the right conditions are present (porous soil, sunlight, minimal watering). But you may have to transplant them to a bigger pot or the ground eventually!